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Last Updated :2024/10/03

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Master

Affiliation (Master)

  • Research Faculty of Agriculture　Fundamental AgriScience Research　Forest Science

Affiliation (Master)

  • Research Faculty of Agriculture　Fundamental AgriScience Research　Forest Science

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Profile and Settings

Degree

  • 1989, 12. PhD of Hokkaido University (Science)（Hokkaido University）

Profile and Settings

  • Name (Japanese)

    Uraki

  • Name (Kana)

    Yasumitsu

  • Name

    200901010222264093

Alternate Names

Achievement

Research Interests

  • 木質資源化学   多糖類化学   高分子化学   Polysaccharide Chemistry   Polymer Chemistry   Wood Chemistry   

Research Areas

  • Life sciences / Wood science
  • Nanotechnology/Materials / Biochemistry
  • Nanotechnology/Materials / Polymer chemistry

Research Experience

  • 2008 - Today Hokkaido University Graduate School of Agriculture Research Faculty of Agriculture
  • 2006 - 2008 - 北海道大学大学院農学研究院 准教授
  • 1999 - 2006 Associate Professor,Graduate School of Agriculture, Hokkaido University
  • 2006 - Associate Professor,Research Faculty of Agriculture, Hokkaido University
  • 1994 - 1999 Hokkaido University Faculty of Agriculture
  • 1994 - 1999 Associate Professor,Faculty of Agriculture, Hokkaido University
  • 1989 - 1994 Hokkaido University Faculty of Agriculture
  • 1989 - 1994 Research Associate,Faculty of Agriculture, Hokkaido University
  • 1987 - 1989 Hokkaido University School of Science
  • 1987 - 1989 Research Associate,Faculty of Science, Hokkaido University

Education

  •        - 1987  Hokkaido University
  •        - 1987  Hokkaido University  Graduate School, Division of Natural Science
  •        - 1986  Hokkaido University
  •        - 1986  Hokkaido University  Graduate School, Division of Natural Science
  •        - 1984  Hokkaido University  School of Science
  •        - 1984  Hokkaido University  Faculty of Science

Awards

  • 2020/09 セルロース学会 セルロース学会賞
     
    受賞者: 浦木康光
  • 2009 第7回北の木材科学賞
  • 2008 第６回北の木材科学賞
  • 2007 第５回北の木材科学賞
  • 2006 第4回北の木材科学賞
  • 2006 日本木材学会賞
  • 2006 The Japan Wood Research Society Prize for 2006
  • 2005 第3回北の木材科学賞
  • 2003 第１回北の木材科学賞

Published Papers

  • Keiichiro Takeuchi, Shiori Suzuki, Kengo Shigetomi, Yasumitsu Uraki
    Journal of Wood Chemistry and Technology 1 - 11 0277-3813 2024/09/12
  • Shogo Taira, Ikuto Tanouchi, Shiori Suzuki, Tadahisa Iwata, Yasumitsu Uraki
    Cellulose 31 (3) 1559 - 1568 2024/02 [Refereed]
  • Fumiya Honda, Shogo Taira, Shiori Suzuki, Kazuhiro Shikinaka, Kengo Shigetomi, Yasumitsu Uraki
    Holzforschung 0018-3830 2023/08/31 [Refereed][Not invited]
     
    Abstract A lignin-based gel prepared by the chemical crosslinking of hardwood acetic acid lignin (AL) with poly(ethylene glycol) diglycidyl ether has been reported to shrink in water and organic solvents but swell specifically in aqueous binary solutions. In this study, the AL-based gel was also found to swell in lithium-salt-containing organic solvents, namely, liquid electrolytes. The uptake of salt solutions reached five times the dry weight of the gel. The ionic conductivity of the gel swollen with 1 M LiBF4 in propylene carbonate or a mixed solution (1:1, v/v) of ethylene carbonate and dimethyl carbonate exceeded 1 mS cm−1 at room temperature (25 °C), suggesting that this gel can be applied as a gel electrolyte for lithium-ion batteries (LIBs). A prototype LIB was assembled with the AL-based gel electrolyte and LiCoO2/graphite-based electrodes and exhibited low bulk and charge transfer resistances of 4.1 and 9.7 Ω, respectively. Moreover, its initial specific capacity reached 104 mAh g−1 at a current density of 28 mA g−1, which is comparable to that of a reference LIB assembled using a commercial polyethylene separator. These results indicate the significant potential of this lignin-based gel for application in energy storage devices.
  • Nutthira Pakkang, Shiori Suzuki, Kengo Shigetomi, Yasumitsu Uraki
    HOLZFORSCHUNG 0018-3830 2022/12 
    This study aimed to assemble a high-performance electric double-layer capacitor (EDLC) using a hardwood kraft lignin (HKL)-based separator and HKL-based electrodes, which were fabricated from a nonwoven mat of electrospun HKL fibers. The separator was prepared by the thermostabilization of the mat derived from a mixed dope of HKL, hexamethylenetetramine, and polyethylene glycol (1.66/0.50/0.09, w/w) for electrospinning. Although a mat-type HKL-based electrode containing conductive carbon black (CB) has been reported to be suitable for a commercial cellulosic separator, this electrode was found to be unsuitable for the HKL-based separator because of its rough surface and poor contact with the separator interface. Hence, a powder-type electrode with a smooth surface was fabricated by grinding the mat, followed by casting with a carboxymethyl cellulose aqueous solution, and its EDLC possessed high energy (49 Wh kg(-1)) and power densities (151 kW kg(-1)). Moreover, to provide a simple process for electrode fabrication, another mat-type electrode was fabricated by adding CB to the mixed dope, followed by electrospinning, carbonization, and steam activation. The resultant EDLC exhibited excellent electrochemical performance with energy (58 Wh kg(-1)) and power densities (55 kW kg(-1)).
  • Kengo Shigetomi, Mana Tokizawa, Yasumitsu Uraki
    Journal of Wood Science 68 (1) 1435-0211 2022/12 
    Abstract To establish a facile methodology for the elucidation of the lignin chain-growth mechanism, the preparation of monolignol that does not show NMR signals in the dehydrogenative polymer (DHP) was attempted. As a monolignol of which aliphatic moieties were deuterated, coniferyl alcohol-d7 was successfully synthesized from protocatechualdehyde and malonic acid via the modified Knoevenagel–Doebner reaction and the Luche reduction. The process achieved high to excellent deuteration efficiencies at the aimed positions (i.e., methoxy: > 99%D, α: > 99%D, β: 92%D, and γ: 98%D). DHP was prepared solely from coniferyl alcohol-d7, and its NMR spectra were compared with those from coniferyl alcohol. The results indicated that: (1) the deuterium atoms at methoxy group, α- and β-positions were highly retained even in the DHP, and their signals were effectively suppressed; (2) a part of the deuterium at γ-position was replaced with H through the reaction; (3) meanwhile, the formation of γ-CH2 was negligible. This study demonstrated that coniferyl alcohol-d7 could “silence” the majority of the signals even when converted to DHP. Highly deuterated monolignols can be a unique molecular tool that can differentiate the signals of interest from those derived from monolignols.
  • Yan Lyu, Shiori Suzuki, Hiroki Nagano, Kengo Shigetomi, Yutaka Tamai, Yuji Tsutsumi, Yasumitsu Uraki
    Carbohydrate Polymers 301 120305 - 120305 0144-8617 2022/11/07 [Refereed]
  • Manish Kumar, Shogo Taira, Nutthira Pakkang, Kengo Shigetomi, Yasumitsu Uraki
    Advances in Natural Sciences: Nanoscience and Nanotechnology 13 (2) 2022/06 
    In this study, lignin-based conducting carbon nanofiber mat was prepared by electrospinning followed by a thermal treatment. Lignin is a sustainable carbon precursor. Polyacrylonitrile (PAN) acts as a binder polymer, which increases the viscosity of the lignin solution using dimethylformamide solvent and helps in the formation of a stable nanofiber. The mixture solution was electrospun, followed by stabilisation and carbonisation to yield carbon nanofibers (CNFs). A fixed amount of external load was provided to the lignin fiber mat during the stabilisation procedure and then carbonised to yield stretched carbon nanofibers (S-CNFs). On stretching the mat, surface conductivity was enhanced by 3 times, and the surface area by 1.3 times compared to that of non-stretched CNFs. Finally, the electric double layer capacitor (EDLC) was assembled with the resulting (CNFs and S-CNFs) nanofiber mat using 6 M of KOH aqueous solution. S-CNFs mat exhibits a specific capacitance of 266 F g−1, which was higher than that of CNFs, i.e. 258 F g−1 at a scan rate of 5 mVs−1
  • Yoshimichi Sakakibara, Yusuke Sai, Yasumitsu Uraki, Makoto Ubukata, Kengo Shigetomi
    HETEROCYCLES 104 (1) 140 - 158 0385-5414 2022 
    The Mitsunobu inversion is one of the reliable methods for stereospecific substitution of chiral alcohols, but its deacylation step has limited the substrate scope. Here, we propose a new template of the Mitsunobu acylate that can be deacylated in non-alkaline treatments. The 3,4-dihydroxy-2-methylenebutanoate was selected as a template structure, and its acetonide- or bisTBS derivatives were synthesized. The latter especially showed excellent inversion efficiency (up to >99% ee) and good elimination performance for a series of secondary alcohols in near-neutral conditions. The results demonstrated the applicability of the new template for the substrates labile in alkaline conditions, such as alpha-hydroxyesters.
  • Yan Lyu, Tatsuya Matsumoto, Shogo Taira, Kazumasa Ijiri, Arata Yoshinaga, Kengo Shigetomi, Yasumitsu Uraki
    Cellulose 28 (15) 9907 - 9917 0969-0239 2021/10 [Refereed]
     
    To elucidate the effects of polysaccharides, cellulose, water-soluble xylan (WXY), galactoglucomannan (GGM) and xyloglucan (XG) on lignification in vitro, artificial polysaccharide matrices were prepared from a combination of cellulose and hemicelluloses, and dehydrogenation polymer (DHP) was synthesized from coniferyl alcohol in the presence of the matrices by using horseradish peroxidase (HRP). Prior to DHP formation, interactions between cellulose and hemicelluloses were investigated with equilibrium adsorptions of the hemicelluloses on bacterial cellulose (BC) films and with quartz crystal microbalance with dissipation technique (QCM-D) to determine their adsorption on cellulose nanofibers (CNFs). Both analyses showed that the order of adsorption amounts was XG > GGM > WXY. The QCM-D experiments also suggested that HRP strongly interacted with cellulose rather than hemicelluloses. The amount of DHP generated in the XG-BC matrix was the largest among the prepared matrices, and XG facilitated the formation of 5–5′ interunitary linkages. Thus, XG must be involved in the lignification in primary wood cell wall. On the other hand, the amount of DHP in the GGM-BC matrix was the smallest, indicating that GGM hampered lignification. Graphic abstract: [Figure not available: see fulltext.]
  • Shogo Taira, Yuriko Usukura, Mitsukuni Nishida, Kengo Shigetomi, Yasumitsu Uraki
    Holzforschung 75 (8) 765 - 772 0018-3830 2021/08/26 
    Abstract A lignin-based gel (AL-PE gel) was obtained from hardwood acetic acid lignin (AL) and poly(ethylene glycol) diglycidyl ether (PE) as a cross-linker at a high AL concentration, while the reaction at a lower AL concentration yielded an amphipathic derivative (am-AL-PE). The gel has been reported to swell in aqueous ethanol but shrink in pure water and ethanol. In the present work, swelling behaviors in other aqueous binary solvents and the swelling mechanism were investigated to explore novel lignin-based functional materials, such as stimuli-and/or environment-responsive gels. The AL-PE gel swelled in aqueous methanol, isopropanol, acetone, and tetrahydrofuran, and the order of swelling in the solvents was consistent with that of the am-AL-PE. Spin-spin relaxation time (T 2 ) measurements with 1H NMR analysis of the gel in aqueous acetone revealed that gel swelling was closely related to an increasing T 2 of acetone bound to the gel network. The nature of the lignin moiety in the gel also enabled a pH response, and the amphipathic nature of the gel provided it with a function as an absorbent for cationic surfactants. The results of this study can contribute to the valorization of lignin as a main component for solvent sensors and environmental purification materials.
  • Yoshimichi Sakakibara, Kota Osada, Yasumitsu Uraki, Makoto Ubukata, Kengo Shigetomi
    Bioscience, Biotechnology, and Biochemistry 85 (2) 215 - 222 2021/02/18 
    ABSTRACT Hinokitiol has a broad antibacterial activity against bacteria and fungi. While its biosynthetic pathway has been intensively studied, its dynamics in natural environments, such as biodegradation pathway, remain unclear. In this study, the authors report a direct deuterium labeling of hinokitiol as a traceable molecular probe to serve those studies. Hinokitiol was subjected to the H2-Pd/C-D2O conditions and deuterated hinokitiol was obtained with excellent deuteration efficiencies and in moderate yield. The 1H and 2H NMR spectra indicated that all ring- and aliphatic hydrogens except that on C-6 were substituted by deuterium. According to the substrate scope and computational chemistry, deuteration on tropolone ring was suggested to proceed via D+-mediated process, and which was supported by the results of the experiment with trifluoroacetic acid and Pd(TPP)4. On the other hand, the deuteration on aliphatic group was predicted to be catalyzed by Pd(II) species.
  • Shiho Takahashi, Yasumitsu Uraki, Tatsuhiko Yamada
    BioResources 16 (1) 1787 - 1797 1930-2126 2021/01/22 [Refereed]
     
    A lignin-based water reducer for concrete was prepared from softwood soda lignin. The soda lignin and the lignin-polyethylene glycol (PEG) derivative were modified with ozone to improve their performance as water reducers. The performance of ozone-treated soda lignin was superior than untreated soda lignin and commercial lignosulfonate-type water reducers in the mortar flow test. The soda lignin treated with a high ozone charge showed better performance than lignin treated with a low ozone charge. The ozone treatment improved the performance of the lignin-PEG derivative water reducer as well. The lignin-PEG derivative water reducer with a longer PEG chain length showed better performance than that of the shorter PEG chain. The zeta potential of cement suspension with the ozone-treated soda lignin showed a higher negative value than the untreated soda lignin. The data of zeta potential analysis suggested that the electrostatic repulsion force of cement particles with the ozone-treated lignin would be larger than the untreated lignin.
  • Nutthira Pakkang, Manish Kumar, Shogo Taira, Keiichi Koda, Kengo Shigetomi, Yasumitsu Uraki
    Holzforschung 74 (6) 577 - 588 0018-3830 2020/06/25 [Refereed]
     
    Abstract This article demonstrates the development of activated carbon fiber electrodes produced from hardwood kraft lignin (HKL) to fabricate electric double layer capacitors (EDLCs) with high energy and power densities using an ionic liquid (IL) electrolyte. A mixture solution of HKL, polyethylene glycol as a sacrificial polymer, and hexamethylenetetramine as a crosslinker in dimethylformamide/acetic acid (6/4) was electrospun, and the obtained fibers were easily thermostabilized, followed by carbonization and steam activation to yield activated carbon fibers (ACFs). The electrochemical performance of EDLCs assembled with the ACFs, 1-ethyl-3-methylimidazolium tetrafluoroborate (EMIBF4) as an IL electrolyte and a cellulosic separator was insufficient due to the low conductivity of the electrode. The conductivity of the electrode was improved successfully by spraying conductive carbon black (CB) onto the fibers mat during electrospinning. The CB containing electrodes with improved conductivity gave the resulting EDLCs a higher electrochemical performance, with an energy density of 91.5 Wh kg−1 and a power density of 76.2 kW kg−1.
  • Linping Wang, Kengo Shigetomi, Keiichi Koda, Aori Gele, Yasumitsu Uraki
    Holzforschung 74 (6) 551 - 558 0018-3830 2020/06/25 [Refereed]
     
    Abstract Size exclusion chromatography with multi-angle laser light-scattering detectors was applied for acetylated softwood and hardwood kraft lignins (Ac-SKL and Ac-HKL) and 8-O-4′ type of linear polymeric lignin model (Ac-M-8O4′) to compare their swelling behaviors. The plot of molar mass (MM) vs. retention time for Ac-M-8O4′ was similar to that of polystyrene, which revealed that Ac-M-8O4′ exhibited swelling behavior that was similar to that of polystyrene. However, the MM values of both Ac-KLs were larger than those of polystyrene standards at any retention time. This difference indicated that both Ac-KLs had a more compact structure than those of polystyrene and Ac-M-8O4′. One hypothesis is that the larger MM of both Ac-KLs stems from their branched structures. To verify this hypothesis, the frequency of 5-5′ interunit linkage in lignin samples was determined by 1H NMR after nitrobenzene oxidation. A linear relationship between MM and 5-5′ abundance was observed in the high MM region.
  • Shogo Taira, Masataka Tsuruhara, Ryo Saito, Keiichi Koda, Yasumitsu Uraki, Haruo Konno, Shu Shimamoto
    Cellulose 27 (9) 4991 - 5001 0969-0239 2020/06 [Refereed]
  • Comparison of Dehydrogenation Polymers by Commercial Enzymes, Laccase from Rhus vernicifera and Horseradish Peroxidase
    Tatsuya Matsumoto, Keiichi Koda, Kengo Shigetomi, Manish Kumar, Yasumitsu Uraki
    Lignin 1 20 - 28 2020/04 [Refereed]
  • Yuu Hasegawa, Mitsunori Mori, Keiichi Koda, Yasumitsu Uraki
    Journal of Wood Chemistry and Technology 40 (1) 1 - 14 0277-3813 2020/01/02 
    Vapor-phase acetylation of heartwood in Japanese cedar wood (Cryptomeria japonica D. Don) was carried out as a surface acetylation method to elucidate the relationship between the depth of acetylated area and fungal decay resistance. The acetylated wood (VPAW), prepared with acetic anhydride vapor by heating at 80 degrees C for 72 h, indicated a significant fungal decay resistance and dimensional stability in water-soaking test, similar to liquid-phase acetylated wood (LPAW). The VPAW provided more than 15% of the weight percent gain (WPG) up to a depth of 7 mm from the wood surface, while LPAW gave similar to 20% WPG uniformly throughout the wood. However, 24-h vapor-phase acetylation, giving 15% WPG at a depth of 0-2 mm, showed insufficient fungal decay resistance. These results showed that at least 7 mm thickness of the acetylated region with 15% WPG was required to suppress the fungal decay of acetylated wood under laboratory conditions.
  • Md. Momotaz Ali, Nutthira Pakkang, Shogo Taira, Keiichi Koda, Koki Itoyama, Yasumitsu Uraki
    Journal of Wood Chemistry and Technology 39 (4) 282 - 295 0277-3813 2019/07/04
  • Keiichi Koda, Shogo Taira, Atsushi Kubota, Tomofumi Isozaki, Xiangyu You, Yasumitsu Uraki, Kazuki Sugimura, Yoshiyuki Nishio
    Journal of Wood Chemistry and Technology 39 (3) 198 - 213 0277-3813 2019/05/04
  • Linping Wang, Yasumitsu Uraki, Keiichi Koda, Aori Gele, Xuesong Zhou, Fangeng Chen
    Holzforschung 73 (4) 363 - 369 0018-3830 2019/04/24 [Refereed]
     
    Abstract The molar mass (MM) and polydispersity indices (PDI) of acetylated hardwood kraft lignin (Ac-HWKL) and Ac-HWKL fractions were measured by size-exclusion chromatography with multi-angle laser light scattering (SEC-MALLS). The detectors worked at LL658 nm and LL785 nm. The MM of Ac-HWKL measured at 785 nm was much smaller than that measured at 658 nm. The number-average (Mn) and weight-average (Mw) molar masses of Ac-HWKL determined at 785 nm were approximately 6.2 and 6.5 times larger, respectively, than the values estimated using a conventional calibration curve created with authentic polystyrene standards in tetrahydrofuran (THF). Based on the Mw of Ac-HWKL fractions, the Mark-Houwink-Sakurada equation for Ac-HWKL was established to be [η]/ml g−1=0.320 M0.24 in THF and [η]/ml g−1=0.142 M0.26 in dimethyl sulfoxide (DMSO). These results demonstrate that Ac-HWKL has a more compact structure in an organic solvent than polystyrene.
  • Shogo Taira, Makoto Kurihara, Keiichi Koda, Kazuki Sugimura, Yoshiyuki Nishio, Yasumitsu Uraki
    Cellulose 26 (1) 569 - 580 0969-0239 2019/01
  • Nutthira Pakkang, Yasumitsu Uraki, Keiichi Koda, Manit Nithitanakul, Ampira Charoensaeng
    Journal of Surfactants and Detergents 21 (6) 809 - 816 1097-3958 2018/11 [Refereed]
  • Ningning Cheng, Keiichi Koda, Yutaka Tamai, Yoko Yamamoto, Taichi E. Takasuka, Yasumitsu Uraki
    BIORESOURCE TECHNOLOGY 232 126 - 132 0960-8524 2017/05 [Refereed][Not invited]
     
    Amphipathic lignin derivatives (A-LDs) prepared from the black liquor of soda pulping of Japanese cedar are strong accelerators for bioethanol production under a fed-batch simultaneous enzymatic saccharification and fermentation (SSF) process. To improve the bioethanol production concentration, conditions such as reaction temperature, stirring program, and A-LDs loadings were optimized in both small scale and large scale fed-batch SSF. The fed-batch SSF in the presence of 3.0 g/L A-LDs at 38 degrees C gave the maximum ethanol production and a high enzyme recovery rate. Furthermore, a jar-fermenter equipped with a powerful mechanical stirrer was designed for 1.5 L-scale fed-batch SSF to achieve rigorous mixing during high substrate loading. Finally, the 1.5 L fed-batch SSF with a substrate loading of 30% (w/v) produced a high ethanol concentration of 87.9 g/L in the presence of A-LDs under optimized conditions. (C) 2017 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
  • Yoko Yamamoto, Ningning Cheng, Keiichi Koda, Kiyohiko Igarashi, Yutaka Tamai, Yasumitsu Uraki
    CELLULOSE 24 (4) 1849 - 1862 0969-0239 2017/04 [Refereed][Not invited]
     
    Amphipathic lignin derivatives (ALDs), prepared from hardwood acetic acid lignin and softwood soda lignin via coupling with a mono-epoxylated polyethylene glycol, have been reported to improve the enzymatic saccharification efficiency of lignocellulose while maintaining significant residual cellulase activity after saccharification. We previously demonstrated that the effect of ALDs was caused by a direct interaction between ALDs and Cel6A (or CBH II). In this study, a different ALD was prepared from softwood kraft lignin in addition to aforementioned ALDs. The interactions between all the ALDs and the enzymes other than Cel6A, such as Cel7A and Cel7B, in a cellulase cocktail were investigated using surface plasmon resonance. The kraft lignin-based ALD showed the highest residual cellulase activity among all ALDs and an improved cellulolytic enzyme efficiency similar to those of the other ALDs. All ALDs were found to directly associate with major enzymes in the cellulase cocktail, Cel6A and Cel7A (or CBH I), but not with Cel7B (or EG I). In addition, the ALDs showed a much higher affinity to amino groups than to hydroxy and carboxy groups. In contrast, polyethylene glycol (molecular mass 4000 Da), one part of the ALD and a previously reported enzymatic saccharification enhancer, did not adsorb onto any enzymes in the cellulase cocktail or the amino group. Size exclusion chromatography demonstrated that the ALDs formed self-aggregates in both water and chloroform; the formation process in the latter was especially unique. Therefore, we conclude that the high residual cellulase activity is attributed to the direct association of ALD aggregates with the CBH group.
  • Ligninolytic Activity at 0 °C of Fungi on Oak Leaves Under Snow Cover in a Mixed Forest in Japan
    T. Miyamoto, K. Koda, A. Kawaguchi, Y. Uraki
    Microbial Ecology 74 (2) 322 - 331 2017/02 [Refereed][Not invited]
  • Xiangyu You, Junlei Duan, Keiichi Koda, Tatsuhiko Yamada, Yasumitsu Uraki
    HOLZFORSCHUNG 70 (7) 661 - 671 0018-3830 2016/07 [Refereed][Not invited]
     
    Electrodes has been prepared for application in an electric double layer capacitor (EDLC) based on polyethylene glycol lignin (PEGL) and soda lignin (SL) derived from cedar wood. Fibers with a diameter of 23 mu m were prepared by direct melt electrospinning of PEGL. Much finer fibers of 3.6 mu m diameter were obtained by dry electrospinning of 70% PEGL in a dimethyl formamide (DMF) solution at 145 degrees C. The dry electrospinning of SL alone in an alkaline aqueous solution was not achievable, but this was possible of a mixture of SL and polyethylene glycol (M-w = 500 000) at a ratio of 99/1, which resulted in thin SL fibers with a diameter of 0.85 mu m. These fibers were converted into activated carbon fibers (ACFs) by thermostabilization, carbonization, and steam activation. The specific Brunauer, Emmett and Teller (BET) surface areas of the resulting PEGL-ACFs and SL-ACFs were 1880 m(2) g(-1) and 1411 m(2) g(-1), respectively. PEGL-ACFs electrodes with an organic electrolyte exhibited an impedance of 1.6 Omega and a specific capacitance of 92.6 F g(-1) at a scan rate of 1 A g(-1), and the SL-ACFs electrodes had an impedance and specific capacitance of 4.5 Omega and 55.6 F g(-1), respectively.
  • Xiangyu You, Keiichi Koda, Tatsuhiko Yamada, Yasumitsu Uraki
    JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY 36 (6) 418 - 431 0277-3813 2016 [Refereed][Not invited]
     
    Activated carbon fibers (ACFs) with large surface area were easily prepared from melt-spun fibers of polyethylene glycol lignin (PEGL). To fabricate electric double-layer capacitors (EDLCs) with a wide potential window and a high energy density in an EDLC package, electrodes (mainly composed of ACFs) were internally laminated and connected in series, in parallel, or in a series/parallel combination. Such resultant EDLCs are termed internal tandem (IT) EDLCs. As expected, the potential window was expanded by the series connection, and the capacitance was increased by the parallel connection. As a result, the energy density in the parallel-connected EDLC was remarkably increased by 66% (16.6 Wh kg(-1)) compared with that of a single-cell EDLC. The EDLC with the combination connection showed both advantages. Thus, based on the package weight, the electrochemical performance of the EDLCs was remarkably improved by the IT-type lamination of electrodes.
  • Xiangyu You, Keiichi Koda, Tatsuhiko Yamada, Yasumitsu Uraki
    JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY 36 (6) 418 - 431 0277-3813 2016 [Refereed][Not invited]
     
    Activated carbon fibers (ACFs) with large surface area were easily prepared from melt-spun fibers of polyethylene glycol lignin (PEGL). To fabricate electric double-layer capacitors (EDLCs) with a wide potential window and a high energy density in an EDLC package, electrodes (mainly composed of ACFs) were internally laminated and connected in series, in parallel, or in a series/parallel combination. Such resultant EDLCs are termed internal tandem (IT) EDLCs. As expected, the potential window was expanded by the series connection, and the capacitance was increased by the parallel connection. As a result, the energy density in the parallel-connected EDLC was remarkably increased by 66% (16.6 Wh kg(-1)) compared with that of a single-cell EDLC. The EDLC with the combination connection showed both advantages. Thus, based on the package weight, the electrochemical performance of the EDLCs was remarkably improved by the IT-type lamination of electrodes.
  • Xiangyu You, Keiichi Koda, Tatsuhiko Yamada, Yasumitsu Uraki
    HOLZFORSCHUNG 69 (9) 1097 - 1106 0018-3830 2015/11 [Refereed][Not invited]
     
    Lignin-based activated carbon fibers (ACFs) were prepared by electrospinning of hardwood acetic acid lignin (HW-AAL) solution followed by thermostabilization, carbonization, and steam activation. The thermostabilization process was able to be remarkably shortened from 38 h to 3 h with hexamethylenetetramine (hexamine) in binary solvents, AcOH/CCl4 (8/2), when compared with conventional thermostabilization processes. The resultant ACFs possessed higher specific surface area (2185 m(2) g(-1)) than those from commercial activated carbon and electrospun lignin fibers without hexamine. These ACFs also exhibited good electrical capacitance (133.3 F g(-1) at a current density of 1 A g(-1)) as electrodes of electric double layer capacitor (EDLC) are efficient not only due to their large surfaces area but also due to their porous structure with well-developed micropores (diameter: 0.5-1.3 nm). High energy density and power density of this EDLC (42 Wh kg(-1) and 91 kW kg(-1), respectively) were also achieved.
  • Qiang Li, Keiichi Koda, Arata Yoshinaga, Keiji Takabe, Masatsugu Shimomura, Yuji Hirai, Yutaka Tamai, Yasumitsu Uraki
    JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 63 (18) 4613 - 4620 0021-8561 2015/05 [Refereed][Not invited]
     
    To elucidate the influence of wood polysaccharide components on lignin formation in vitro, models for polysaccharide matrix in wood secondary cell wall were fabricated from two types of bacterial cellulosic films, flat film (FBC) and honeycomb-patterned film (HPBC), as basic frameworks by depositing xylan onto the films. An endwise type of dehydrogenative polymerization, Zutropfverfahren, of coniferyl alcohol was attempted in the films with/without xylan. The resultant dehydrogenation polymer (DHP) was generated inside and outside xylan-deposited films, whereas DHP was deposited only outside the films without xylan. The amount of the generated DHP in the xylan-deposited films was larger than that in the films without xylan. The frequency of 8-O-4' interunitary linkage in DHP was also increased by the xylan deposition. These results suggest that xylan acts as a scaffold for DHP deposition in polysaccharides matrix and as a structure regulator for the formation of the 8-O-4' linkage. In addition, mechanical properties, i.e., tensile strength and modulus of elasticity (MOE), of both cellulosic films were found to be augmented by the deposition of xylan and DHP. Especially, DHP deposition remarkably enhanced MOE. Such effects of xylan on DHP formation and augmentation of mechanical strength were clearly observed for HPBC, revealing that HPBC is a promising framework model to investigate wood cell wall formation in vitro.
  • Yamamoto Yoko, Cheng Ningning, Igarashi Kiyohiko, Koda Keiichi, Uraki Yasumitsu
    ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY 249 0065-7727 2015/03/22 [Refereed][Not invited]
  • Kukjin Yoon, Shiho Takahashi, Thi Thi Nge, Olov Karlsson, Akiko Nakagawaizumi, Hiroshi Ohi, Yasumitsu Uraki, Tatsuhiko Yamada
    BIORESOURCES 10 (1) 912 - 921 1930-2126 2015 [Refereed][Not invited]
     
    Softwood lignin prepared by soda-anthraquinone (AQ) cooking does not have thermal melting characteristics. To improve the properties of softwood soda-AQ lignin, we have invented a new method of lignin modification using dried black liquor powder by a spray dryer system and polyethylene glycol (PEG). In this process, black liquor powder was directly treated with PEG under alkaline conditions to produce PEG-modified lignin (alkaline PEG treatment). Dried black liquor powder prepared by a spray dryer was dissolved into PEG and heated at either 120 or 160 degrees C at atmospheric pressure. The modified lignin (alkaline PEG-treated lignin) was precipitated with acid and recovered by filtration. The alkaline PEG-treated lignin showed adequate thermal melting characteristics. The treatment temperature and the molecular weights of PEG considerably affected the thermal properties of the alkaline PEG-treated lignin. There was an addition reaction of the PEG to the lignin hydroxyl group at the alpha-(alpha-) carbon. However, in the acid precipitation step, if the mixture was allowed to set unfiltered for a long time, the PEG bonded with the lignin was hydrolyzed, which yielded the original soda-AQ lignin and PEG polymer.
  • Shiho Takahashi, Shuji Hosoya, Masami Hattori, Masakazu Morimoto, Yasumitsu Uraki, Tatsuhiko Yamada
    JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY 35 (5) 348 - 354 0277-3813 2015 [Refereed][Not invited]
     
    We have developed a high-performance lignin-based water-reducing admixture. In this study, softwood soda-anthraquinone lignin was modified with mono-epoxide polyethylene glycols having chain lengths of 10, 25, and 50 mol (the number of repeating units of ethylene oxide). The mortar flow and concrete slump flow tests were used to investigate the performance of the lignin derivatives as a water-reducing admixture. All tested lignin-PEG derivatives performed considerably better than a commercial lignosulfonate water-reducing admixture in the mortar flow test. In particular, the derivative with a PEG chain length of 50 mol performed excellently in both tests. The optimum PEG content for mortar dispersion was approximately 40% for lignin derivatives with a PEG chain length of 50 mol; this content exhibited a dispersing effect that was four times higher than that of the lignosulfonate water-reducing admixture. The strength of concrete containing the lignin derivatives was almost the same strength as that of concrete containing the commercial lignosulfonate water-reducing admixture.
  • Ningning Cheng, Yoko Yamamoto, Keiichi Koda, Yutaka Tamai, Yasumitsu Uraki
    BIORESOURCE TECHNOLOGY 173 104 - 109 0960-8524 2014/12 [Refereed][Not invited]
     
    Amphipathic lignin derivatives (A-LDs) were already demonstrated to improve enzymatic saccharification of lignocellulose. Based on this knowledge, two kinds of A-LDs prepared from black liquor of soda pulping of Japanese cedar were applied to a fed-batch simultaneous saccharification and fermentation (SSF) process for unbleached soda pulp of Japanese cedar to produce bioethanol. Both lignin derivatives slightly accelerated yeast fermentation of glucose but not inhibited it. In addition, ethanol yields based on the theoretical maximum ethanol production in the fed-batch SSF process was increased from 49% without A-LDs to 64% in the presence of A-LDs. (C) 2014 Elsevier Ltd. All rights reserved.
  • Ina Winarni, Keiichi Koda, Totok K. Waluyo, Gustan Pari, Yasumitsu Uraki
    JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY 34 (3) 157 - 168 0277-3813 2014/07 [Refereed][Not invited]
     
    The aim of this research is to develop an enzymatic saccharification process of sago starch waste, with a small charge of cellulase. The waste contained a significant amount of residual starch, which was recovered as glucose by mild acid hydrolysis. The starch-free residue was subjected to soda-anthraquinone pulping to yield soda pulp and soda lignin. The lignin was converted to amphipathic lignin derivatives by the reaction with epoxylated polyethylene glycol analogues. The pulp was hydrolyzed with cellulase (Genencor GC220), with the amphipathic derivatives, to yield glucose. The lignin derivative-assisted, enzymatic saccharification was repeatedly conducted by reusing cellulase recovered by ultrafiltration from saccharification media. Saccharification efficiency with the derivatives was maintained at a high level even after the fourth run of saccharification, while the efficiency was remarkably decreased by repeated use of cellulase without additive. Thus, the amphipathic sago lignin derivatives enabled repeated use of cellulase for saccharification of sago starch waste.
  • Jian Lin, Keiichi Koda, Satoshi Kubo, Tatsuhiko Yamada, Makiko Enoki, Yasumitsu Uraki
    JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY 34 (2) 111 - 121 0277-3813 2014/06 [Refereed][Not invited]
     
    PEG-lignin fibers obtained by a solvolysis pulping of Japanese cedar with polyethylene glycol (PEG) 400 were successfully converted into defective-free, infusible fibers as a precursor for carbon fibers (CFs) by chemical curing followed by oxidative thermostabilization. The curing was performed by immersing PEG-lignin fibers in an aqueous mixed solution of hexamethylenetetramine (60g/L) and hydrochloric acid (3M) at 85 degrees C for 1h, resulting in the formation of crosslinkages between lignin molecules through methylene groups. These cured fibers were completely thermostabilized upon heating up to 250 degrees C at a heating rate of 2 degrees C/min under an air atmosphere. Finally, the thermostabilized fibers were carbonized to yield CFs, which showed about 1.5times the tensile strength of our CFs previously prepared.
  • ShihoTakahashi, Masami Hattori, Masakazu Morimoto, Yasumitsu Uraki, Tatsuhiko Yamada
    Journal of Wood Chemistry and Technology 34 31 - 38 2014/01 [Refereed][Not invited]
  • Tomohiro Aso, Keiichi Koda, Satoshi Kubo, Tatsuhiko Yamada, Isamu Nakajima, Yasumitsu Uraki
    Journal of Wood Chemistry and Technology 33 (4) 286 - 298 2013 [Refereed][Not invited]
  • Ina Winarni, Chihiro Oikawa, Tatsuhiko Yamada, Kiyohiko Igarashi, Keiichi Koda, Yasumitsu Uraki
    BIORESOURCES 8 (2) 2195 - 2208 1930-2126 2013 [Refereed][Not invited]
     
    Synthesized amphipathic lignin derivatives comprised of acidic acid lignin (AL) with poly(ethylene glycol) diglycidyl ether (PEGDE), ethoxy-(2-hydroxy)-propoxy-poly(ethylene glycol) glycidyl ether (EPEG) or dodecyloxy-poly(ethylene glycol) glycidyl ether (DAEO) were added before the enzymatic saccharification of unbleached cedar pulp along with two commercially available cellulases, Meicelase and Genencor GC220. At the same filter paper unit (FPU) dosage, GC220 showed higher sugar yield than Meicelase. The difference was attributed to the composition of processive and non-processive endoglucanase activities per FPU; GC220 had higher such activities than Meicelase. The sugar yield was significantly improved by the addition of the lignin derivatives. In addition, residual activities after the saccharification were maintained at the higher level by their addition than with polyethylene glycol (PEG) 4000. In particular, EPEG-AL yielded the complete recovery of cellulase activity when using 20 FPU/g of substrate. It was found that the lignin derivatives were directly associated with Cel6A, one of cellulase components, whereas PEG 4000 was not. Thus, it is evident that the lignin derivatives are promising agents to improve the enzymatic saccharification of cellulase.
  • URAKI Yasumitsu
    JAPAN TAPPI JOURNAL 紙パルプ技術協会 66 (10) 1120 - 1125 0022-815X 2012/10/01 
    To establish chemical biorefinery for woody biomass, it is very important to convert lignin into value-added materials in addition to its use as an energy source. In this report, I would like to introduce its conversion to several valuable, functional materials on the basis of our recent research.
    The first example is lignin-based carbon fibers (CF). In their production, spinning is a first process. There are proposed two methods, melt spinning and electro-spinning. The latter method for lignin was reported in the last decade. The second process is thermostabilization. The resultant lignin fibers prepared by both methods have high thermal mobility, such as glass transition and thermal flow. Thereby, the fiber morphology is changed by direct carbonization. To prevent morphological change, the thermostabilization process is very important. However, it is a tedious and time-consuming process. We developed a novel type of lignin fibers, which was easily converted into thermally stable fibers by the treatment with concentrated hydrochloric acid for 2 hs. The final product, CF, prepared from the lignin fibers had comparable tensile strength to lignin-based CF reported previously.
    The other example for lignin-based functional materials is amphiphilic lignin derivatives, which are obtained by the reaction of isolated lignins or kraft black liquor with epoxylated polyethylene glycol. When these lignin derivatives were added to a saccharification medium using cellulase, the enzymatic saccharification efficiency was improved and residual activity of cellulase was maintained at a higher level. In addition, one type of the amphiphilic lignin derivative also had a superior ability for the cement dispersion to commercially available lignosulfonate that is well known as a cement dispersant.
  • Yasumitsu Uraki, Yusuke Sugiyama, Keiichi Koda, Satoshi Kubo, Takao Kishimoto, John F. Kadla
    BIOMACROMOLECULES 13 (3) 867 - 872 1525-7797 2012/03 [Refereed][Not invited]
     
    Several lignin model polymers and their derivatives comprised exclusively of beta-O-4 or 8-O-4' interunitary linkages were synthesized to better understand the relation between the thermal mobility of lignin, in particular, thermal fusibility and its chemical structure; an area of critical importance with respect to the biorefining of woody biomass and the future forest products industry. The phenylethane (C6-C2)-type lignin model (polymer 1) exhibited thermal fusibility, transforming into the rubbery/liquid phase upon exposure to increasing temperature, whereas the phenylpropane (C6-C3)-type model (polymer 2) did not, forming a char at higher temperature. However, modifying the C gamma or 9-carbon in polymer 2 to the corresponding ethyl ester or acetate derivative imparted thermal fusibility into this previously infusible polymer. FT-IR analyses confirmed differences in hydrogen bonding between the two model lignins. Both polymers had weak intramolecular hydrogen bonds, but polymer 2 exhibited stronger intermolecular hydrogen bonding involving the C gamma-hydroxyl group. This intermolecular interaction is responsible for suppressing the thermal mobility of the C6-C3-type model, resulting in the observed infusibility and charring at high temperatures. In fact, the C gamma-hydroxyl group and the corresponding intermolecular hydrogen bonding interactions likely play a dominant role in the infusibility of most native lignins.
  • Tomohiro Aso, Keiichi Koda, Satoshi Kubo, Tatsuhiko Yamada, Isamu Nakajima, Yasumitsu Uraki
    PROCEEDING OF THE 4TH INTERNATIONAL CONFERENCE ON PULPING, PAPERMAKING AND BIOTECHNOLOGY (ICPPB '12), VOLS. I AND II 90 - 93 2012 [Refereed][Not invited]
     
    Novel, non-ionic type cement dispersants were prepared from various isolated lignins, softwood and hardwood haft lignins, black liquors from softwood and hardwood haft pulpings, and softwood soda lignin by the reaction with several epoxylated polyethylene glycol (PEG) derivatives, polyethylene glycol diglycidylether (PEGDE), its monoglycidyl ether (EPEG) and dodecyloxypolyethylene glycol glycidyl ether (DAEO). Cement dispersibility of the resultant lignin-based derivatives were examined at 6 C and 20 degrees C. EPEG- and PEGDE-based lignin derivatives gave higher dispersity of cement than lignosulfonate (LS) at both temperatures. Among all the lignin derivatives, EPEG-softwood haft lignin showed the highest cement dispersibility. On the other hand, DAEO-based derivatives did not exhibit cement dispersibility in spite of the fact that it showed the highest surface activity. Thus, it was found that there was no correlation between cement dispersibility and surface activity of lignin-based amphiphiles.
  • Jian Lin, Satoshi Kubo, Tatsuhiko Yamada, Keiichi Koda, Yasumitsu Uraki
    PROCEEDING OF THE 4TH INTERNATIONAL CONFERENCE ON PULPING, PAPERMAKING AND BIOTECHNOLOGY (ICPPB '12), VOLS. I AND II 860 - 863 2012 [Refereed][Not invited]
     
    Solvolysis of cedar Wood with a mixture of polyethylene glycol 400 (PEG 400) and sulfuric acid gave thermally fusible softwood lignin (PEG-lignin), which was easily spun into fibers by melt-spinning at a temperature range of 145 to 172 degrees C without any modification. It took more than 2 days to convert the fibers into thermostabilized ones by the oxidation under air or oxygen atmosphere; that is termed as "conventional thermostabilization". As a shortening process, we developed "chemical thermostabilization"; the PEG-lignin fibers were converted into infusible fibers as a precursor for carbon fibers (CFs) by immersing at 100 degrees C for 2 h. CFs with a tensile strength of 450 MPa were obtained by carbonization at 1000 degrees C under a N-2 stream. The resultant CFs were, in turn, readily converted to activated CFs with large specific surface area of 3060 m(2)/g by the steam activation. This effective activation was attributed to defects generated by chemical thermostabilization, from which the activation proceeded into inside of fibers.
  • Masato Ogawa, Teuku B. Bardant, Yasutaka Sasaki, Yutaka Tamai, Seiichi Tokura, Yasumits Uraki
    BIORESOURCES 7 (1) 236 - 245 1930-2126 2012 [Refereed][Not invited]
     
    Activated carbons (ACs) were prepared from biomass of Borneo island (wood charcoal, peat, and coconut husk) by using an electricity-free furnace, of which the energy source was exclusively wood charcoal. This furnace was comprised of two parts, an inner vessel equipped with water inlet for steam activation and an outer shell as a heating part for the inner vessel. The inside temperature of the inner vessel was able to reach over 1000 degrees C. Peat and wood charcoal were converted to AC by carbonization followed by steam activation, and the specific BET surface areas of resultant ACs were 889 m(2)/g and 749 m(2)/g, respectively. A mobile apparatus for water purification was newly designed and fabricated with the resultant AC, together with a white quartz sand, which is called keranggas in Kalimantan. The CODOH of both polluted creek water by the University of Palangka Raya and Kahayan River water were remarkably decreased by the purification with the designed apparatus from 20.0 mgO/L to 0.93 mgO/L, and 18.2 mgO/L to 0.74 mgO/L, respectively. Thus, the newly designed furnace and purification apparatus were shown to be highly effective tools to produce a promising agent for water purification and to produce clarified water without use of electricity, respectively.
  • Jian Lin, Satoshi Kubo, Tatsuhiko Yamada, Keiichi Koda, Yasumitsu Uraki
    BIORESOURCES 7 (4) 5634 - 5646 1930-2126 2012 [Refereed][Not invited]
     
    A thermally fusible softwood lignin was directly isolated by a solvolysis of cedar wood chips with a mixture of polyethylene glycol 400 (PEG 400) and sulfuric acid. Its fusibility was found to be due to a PEG moiety introduced into the lignin by the solvolysis. The lignin was easily formed into fibers by melt-spinning at temperatures ranging from 145 to 172 degrees C without any modification. The lignin fibers could be converted into infusible fibers as a precursor for carbon fibers (CFs) by conventional oxidative thermal stabilization processing in air or a stream of oxygen for 2 days. We found that the infusible fibers resulted from the partial cleavage of the PEG moiety from the lignin fibers after treatment with 6 M hydrochloric acid at 100 degrees C for 2 h. The infusible fibers were converted into CFs with a tensile strength of 450 MPa by carbonization at 1000 degrees C under a N-2 stream.
  • Yasumitsu Uraki, Keiichi Koda, Tatsuhiko Yamada, Chihiro Oikawa, Tomohiro Aso
    FUNCTIONAL MATERIALS FROM RENEWABLE SOURCES 1107 243 - + 0097-6156 2012 [Refereed][Not invited]
     
    Technical lignins including water-insoluble isolated lignins were easily converted to water-soluble derivatives by the reaction with several types of epoxidized polyethylene glycol derivatives. The resulting lignin-based derivatives were soluble in water and organic solvents, thus having amphiphilic property. We found novel functions of the amphiphiles, such as the uses as cellulase-aid agent and cement dispersant in addition to the surfactant action. This article reviews the functions in relation to the development of biorefining processes for Japanese woody biomass.
  • Kubo Satoshi, Yamada Tatsuhiko, Honma Harumi, Uraki Yasumitsu
    Proceedings of the Conference on Biomass Science 一般社団法人日本エネルギー学会 4 66 - 67 2009 
    Japanese cedar was subjected to the acid catalyzed solvolysis using a mixed solvent of glycols and cyclic carbonates. In this one step solvolysis, lignin having oxyalkyl chains such as polyethylene glycol (EG) chains was prepared together with furfurals and levulinic acid from carbohydrate components. Solvolysis lignin was expected to be utilized as macromolecular surfactants from its amphiphile like chemical structure. However, dissolution properties to water and/or chain flexibility of introduced oxyalkyl chains of solvolysis lignin must be improved for the surfactant application. Another possibility of the solvolysis lignin could be found in the plastic applications. Thermal molding abilities of solvolysis lignin could be improved by the introduction of propylene glycol units in oxyalkyl chains instead of EG units. Solvolysis lignins having polypropylene glycol chains could be spun continuously by melt spinning using a laboratory mixing extruder. This lignin fibre could be thermally stabilized by removing PPG chains through a simple acid washing process. This result would indicate that solvolysis lignin fibres could be converted into carbon fibers with simplified process.
  • Harumi Homma, Yasumitsu Uraki, Makoto Ubukata, Satoshi Kubo, Tatsuhiko Yamada
    PROCEEDINGS OF INTERNATIONAL CONFERENCE ON PULPING, PAPERMAKING AND BIOTECHNOLOGY 2008: ICPPB '08, VOL I 654 - 658 2008 [Refereed][Not invited]
     
    Amphiphilic lignin derivatives were prepared by the polyoxyethylation of acetic acid lignin (AL) using commerclaily available polyethylene glycol diglycidylethers (PEGDE) with 1, 9, 13 and 22 of the repeating unit number (n) of ethylene oxide (EO) in order to make use of them as a nonionic polymeric surfactant. The resultant derivatives revealed significant surface activity, such as reduction of water surface tension and obvious critical micelle concentrations (CMC), although both PEGDE and PEG showed very week. The CIVIC was comparable to a commercial anionic lignin surfactant, lingosulfonate, but was much higher than that of Triton (R) X-100 that was commercial PEG-based nonionic surfactant. The surface activity of AL derivative was further improved by the reaction with monoepoxide compound, ethoxy-(2-hydroxy)-propoxy- polyethylene glycol glycidylether (EPEGGE). The surface tension of water was depressed by the addition of the EPEGGE-AL preparation to the same level as that with Triton (R) X-100, although CMC was still higher.
  • Yoshie Kanazawa, Takao Kishimoto, Keiichi Koda, Kazuhiko Fukushima, Yasumitsu Uraki
    PROCEEDINGS OF INTERNATIONAL CONFERENCE ON PULPING, PAPERMAKING AND BIOTECHNOLOGY 2008: ICPPB '08, VOL I 659 - 663 2008 [Refereed][Not invited]
     
    Non-phenolic and phenolic lignin-dimeric model compounds and a beta-O-4 type artificial lignin polymer have been subjected to thioacidolysis with ethanethiol and boron tribromide etherate to evaluate the reaction efficiency of thioacidolysis for cleavage of beta-O-4 linkage. The obtained yields of thioacidolysis products from dimeric model compounds reached nearly 100% under conventional thioacidolysis conditions, whereas those for the artificial lignin polymer were only at around 70%. Neither prolonged reaction time nor increasing In the concentration of the thioacidolysis reagent enhanced the yields of thioacidolysis products. Thioacidolysis of the lignin models followed by high performance size exclusion chromatographic (HPSEC) analysis also showed that dimeric model compound was degraded almost quantitatively, but artificial lignin polymer was not. These results suggested that conventional thioacidolysis could not achieve quantitative cleavage beta-O-4 linkages in lignin macromolecules.
  • 浦木 康光
    繊維学会誌 The Society of Fiber Science and Technology, Japan 63 (1) P.18 - P.22 0037-9875 2007
  • Uraki Y, Matsumoto C, Kishimoto T, Ubukata M, Yabu H, Tanaka M, Shimomura M
    Abstracts of Papers of the American Chemical Society 233 739  2007 [Refereed][Not invited]
  • Yasumitsu Uraki, Satoshi Kubo
    MOKUZAI GAKKAISHI 52 (6) 337 - 343 0021-4795 2006 [Refereed][Not invited]
     
    Fibrous carbons, such as carbon fibers and activated carbon fibers, have valuable functions as industrial precursors for the production of carbon fiber-reinforced plastics, adsorbents and so on. Approaching global environmental issues are leading toward the utilization of biomass-derived carbonaceous materials to replace the current petrochemical-based industry Woody biomass is comprised of multiple components resulting from highly complex metabolic systems. It is therefore more difficult to produce functional carbonaceous materials directly from woody biomass as compared to fossil resources. These disadvantages of the direct utilization of woody biomass have promoted approaches to establish effective systems for biomass refining into its components, and even to develop new functionalities for biomass carbons with defined differentiation from fossil-based carbons. In this review, current developments of woody biomass-based fibrous carbons are introduced.
  • Uraki Yasumitsu, Matsumoto Chiaki, Tamai Yutaka, Kishimoto Takao, Ubukata Makoto, Yabu Hiroshi, Tanaka Masaru, Shimomura Masatsugu, Beihai H, Shiya F, Fangeng C
    Research Progress in Pulping and Papermaking, 2006 898 - 903 2006 [Refereed][Not invited]
  • Synthesis of polymeric lignin model compounds composed of β-O-4 structure and their analysis by MALDI-TOF-MS
    Takao Kishimoto, Yasumitsu Uraki, Makoto Ubukata
    Appita Annual Conference 2 345 - 348 1443-5454 2005 
    The β-O-4 structure is the most abundant substructure in lignin. Lignin related polymers composed of only β-O-4, structure were prepared from simple aromatic compounds as starting materials. Acetophenone derivatives were brominated, polymerized in the presence of K2CO3, and reduced with NaBH4 to give the lignin related polymers. They are linear polymers which resemble natural lignins in their structure, although they do not have γ-hydroxymethyl group. The number average degree of polymerization (DPn) was determined with peracetate of the polymers by gel permeation chromatography. DPn of guaiacyl type polymers were 15.2-21.4, where syringyl type 11.3 andp-hydroxyphenyl type 16.9. Very resenctly, we have suceeded in the chemical synthesis of β-O-4 type lignin polymer with three-carbon side chain, as well. DPn and DPw reached 15.8 and 30.6, respectively.
  • Delignification mechanism during high-boiling solvent pulping. Part 6: Changes in lignin structure analyzed by 1H-13C correlation 2-D NMR spectroscopy
    Kishimoto T, Ueki A, Takamori H, Uraki Y, Ubukata M
    Organic & Biomolecular Chemistry 3 1067 - 1073 2005 [Refereed][Not invited]
  • Kishimoto, T, Y. Uraki, M. Ubukata
    Org. Biomol. Chem. 3 (6) 1067 - 1073 2005 [Refereed][Not invited]
  • Uraki Y, Otsuka H, Ubukata M, Yabu H, Tanaka M, Shimomura M
    Polymer Preprints, Japan 54 (1) 1561  2005 [Refereed][Not invited]
  • Nemoto J, Uraki Y, Kishimoto T, Sano Y, Funada R, Obata N, Yabu H, Tanaka M, Shimomura M
    Bioresource Technology 96 (17) 1955 - 1958 0960-8524 2005 [Refereed][Not invited]
  • A Nakamura, Y Uraki, T Kishimoto, M Ubukata
    2nd International Symposium on Technologies Of Pulping, Papermaking and Biotechnology on Fiber Plants, Proceedings 521 - 524 2004 [Refereed][Not invited]
     
    An aim of this study was to investigate interactions of a monolignol [coniferyl alcohol (CA)] and its glucoside [coniferin (CR)] with xylan as one of hemicellulose by using the surface plasmon resonance (Biacore TM) to clarify the tranportation of lignin precursor from cell in the lignification process. Xylan isolated from birch was oxidized with periodate to generate aldehyde group, and then the resulting xylan was immobilized onto carboxymethyl (CM)-dextran as a support of sensor chip by the reductive amination to give a ligand on the sensor chip. Various concentrations of CA and CR in aqueous solution as analytes were introduced into the ligand, and adsorption was monitored on the basis of the surface plasmon resonance. As a result, the adsorption capacity of the oxidized xylan to CA was much larger than that of CR. The xylan had high affinity to monolignol. It is proposed that monolignol could be supplied from cytoplasm for ligninfication but not its glucoside.
  • T Imura, Y Uraki, T Kisimoto, M Ubukata
    2nd International Symposium on Technologies Of Pulping, Papermaking and Biotechnology on Fiber Plants, Proceedings 591 - 594 2004 [Refereed][Not invited]
     
    Hydroxypropyl-cellulose bearing lignin (HPC-L) and hydroxypropyl-cellulose (HPC) were preprared from the unbleached acetic acid pulp and pure cellulose by hydroxypropylation using propylene oxide. The HPC-L showed the lower critical solution temperature (LCST) at 38 degrees C, which was five degree lower than that of HPC. These HPC preparations were converted to urethane- and epoxy-types of chemical gels by crosslinking using hexamethylene diisocyanate (HDI) and ethylene glycol diglycidyl ether (EGDE), respectively. These gels markedly shrank in water upon heating. All the urethane-type gels began shrinking at 20 degrees C. On the other hand, the epoxy-types gels shrank at higher temperatures. The epoxy-type of HPC-L gel indicated the drastic shrinking at 38 degrees C, while the corresponding HPC gel showed the half volume at approximate 45 degrees C. Therefore, the epoxy-type of HPC-L gel is considered as a body-temperature responsive gel. These shrinking behaviors reflect the LCST of the original HP-derivatives in aqueous solution. The difference in the LCST and the temperature of gel shrinking between HPC-L and HPC were attributable to the hydrophobicity of the residual lignin.
  • M Nishida, Y Uraki, Y Sano
    BIORESOURCE TECHNOLOGY 88 (1) 81 - 83 0960-8524 2003/05 [Refereed][Not invited]
     
    Lignin gels were prepared from acetic acid lignin by use of polyethylene glycol diglycidyl ether as cross-linker. The gels were found to swell in aqueous ethanol solution, in particular 50% (v/v) solution. In addition, they also swelled in alkaline solution and shrank upon heating. A literature search showed that investigation on gel swelling in aqueous ethanol has not been reported so far. Gels prepared from the cross-linker alone and its analogues did not show such swelling characteristics in aqueous ethanol. Therefore, the unique swelling property must be attributable to an intrinsic property of lignin. (C) 2002 Elsevier Science Ltd. All rights reserved.
  • T Kishimoto, H Tsuji, Y Uraki, Y Sano
    HOLZFORSCHUNG 57 (2) 181 - 188 0018-3830 2003 [Refereed][Not invited]
     
    Atmospheric acetic acid pulp from Japanese white birch was bleached with 1-5% ozone with and without intermediate mild alkaline extraction. Concentrated acetic acid was a more effective bleaching media than water. Mild alkaline extraction of ozone-prebleached pulp was found to be very effective in delignification of the pulp and did not have any undesirable effects on pulp properties. A sufficiently delignified acetic acid pulp was obtained with inulti-stage ozone bleaching in Z(1)Z(2)Z(3) or Z(1)EZ(2)EZ(3) bleaching sequence with a total ozone consumption of 2.17% on oven-dry pulp. The pulp from a Z(1)EZ(2)EZ(3) sequence still contained 3.51% acetyl groups, which was 75% of the original amount of acetyl groups in unbleached acetic acid pulp.
  • J Nemoto, Y Uraki, Y Sano
    MOKUZAI GAKKAISHI 49 (4) 287 - 292 0021-4795 2003 [Refereed][Not invited]
     
    Attempts were made to prepare board-shaped moldings for use as paper receptacles and structural materials. Composites of six kinds of isolated lignins and four kinds of waste paper were made by dry-forming and wet-forming methods. Board properties, such as flexural strength and water resistance, were examined with respect to component materials and to molding conditions. Excellent boards with the highest modulus of rupture (MOR) and the lowest water adsorption (WA) could be obtained from hardwood (H) and softwood (S) acetic acid lignin (AL) among the isolated lignins tested, and from waste newspaper among the waste paper. Technical lignins, such as kraft lignin and lignosulfonate, were not promising sources for boards because of low water resistance. The HAL-waste newspaper board showed maximal MOR when it composed of 15% of HAL. WA was reduced with increasing HAL content and molding temperature. Furthermore, MOR of boards was improved by partially replacing the lignin with either phenolic resin or biodegradable polyester. Comparing the forming processes, wet-formed boards had better properties than did dry-formed one; HAL 40% board with a density 1.4 g/cm(3) had an MOR of 68 MPa and WA of 4%. These results suggest that the AL acts as an adhesive for improving board strength. In addition, it gives the boards water resistance.
  • URAKI Yasumitsu, MIHARU Yousuke, FUNADA Ryo, SANO Yoshihiro, MITSUHASHI Masaki, ITOYAMA Kohki, TANIBE Hiroaki
    Sen-ito Kogyo The Society of Fiber Science and Technology, Japan 56 (10) 482 - 486 0037-9875 2000/10/10 
    Alginate-blended rayon was prepared from a mixture of alginate and cellulose xantate in alkaline solution. Wide distribution of alginate in the whole fiber was revealed by scanning electron microscopy-energy dispersive X-ray microanalysis (SEM-EDX) and confocal laser scanning microscopy. The alginate blended in the rayon could not be removed by aqueous alkaline solution completely, suggesting that a part of the blended alginate formed tight complex with cellulose. The blended rayon had an excellent moisture sorption property such as a superior moisture sorption and a comparable heat of sorption to those of wool.
  • Y Uraki, S Kubo, H Kurakami, Y Sano
    HOLZFORSCHUNG 51 (2) 188 - 192 0018-3830 1997 [Refereed][Not invited]
     
    Activated carbon fibers (ACF's) were prepared from acetic acid lignin-based carbon fibers by steam activation. The ACF had excellent properties, such as more rapid adsorption rate and higher iodine and methylene blue adsorption capacities, as compared to a commercially available activated carbon. The adsorption mechanism of ACF was quite different from that of activated carbon (AC), as supported by the micropore distribution profiles.
  • Satoshi Kubo, Yasumitsu Uraki, Yoshihiro Sano
    Holzforschung 50 (2) 144 - 150 0018-3830 1996 [Refereed][Not invited]
     
    The thermal behavior of kraft lignin (KRL), periodate lignin (PIL), steam-exploded lignin (SEL) and acetic acid lignin (AAL), with emphasis on changes in volume upon heating, was investigated by thermomechanical analysis (TMA) in an attempt to evaluate the fusibility of lignin. All lignins underwent a glass transition but, with the exception of AAL, they all had infusible characteristics. The TMA curve for birch AAL (B-AAL) revealed two clear inflection points, assigned to the glass transition point (Tg) and the softening point (Ts) for transformation into a fluid liquid. Thus, only B-AAL among the lignins examined in this study had a fusion state. A fraction of B-AAL with almost the same weight-average relative molecular mass (Mw) as original B-AAL but with less polydispersity was found not to be transformed into a fused state. By contrast, fractions with lower relative molecular mass, namely, with Mw of less than 1,000, which accounted for 30% of AAL, had good fusibility. Therefore, the low-Mw fractions were responsible for the fusibility of B-AAL. Thermostable fusion states of acetylated KRL could not be confirmed by results of TMA and visual inspection. Thus, lignins could not be converted to fusible materials solely by the introduction of acetyl groups. Furthermore, from the results of TMA of fir AAL (F-AAL), which did not have a clear fusion state, it appeared that the fusibility of lignins was related to their molecular structures, for example, the extent of condensation of aromatic nuclei.
  • Y URAKI, S KUBO, N NIGO, Y SANO, T SASAYA
    HOLZFORSCHUNG 49 (4) 343 - 350 0018-3830 1995 [Refereed][Not invited]
     
    Lignin fibers as precursors for carbon fibers were prepared by melt spinning from organosolv lignin (AWL), which was obtained from birch wood by aqueous acetic acid pulping at atmospheric pressure and used without any chemical modification. The spinnability of AWL was attributable to polydispersity of the lignin and to partial acetylation of hydroxyl groups during the pulping. Production of satisfactory lignin fibers was achieved by simple thermal treatment of lignin, followed by continuous spinning at a rate of more than 400m/min. The thermostabilization of thin (less than 30 mu m in diameter) and thick threads was achieved by heating to 250 degrees C at a rate of 0.5 degrees C/min in air and under oxygen stream, respectively. Carbonization of thermostable fibers was achieved by heating to 1,000 degrees C under nitrogen stream. The mechanical strength of the carbon fibers was found to be related to the diameter of fibers. Typical mechanical properties of carbon fibers from AWL were as follows: fiber diameter 14 +/- 1.0 mu m; elongation, 0.98 +/- 0.25%; tensile strength, 355 +/- 53 MPa; modulus of elasticity, 39.1 +/- 13.3 GPa. The carbon fibers derived from AWL can be classified as fibers of general performance grade.
  • Yasumitsu Uraki, Seiichi Tokura
    Journal of Macromolecular Science: Part A - Chemistry 25 (10-11) 1427 - 1441 0022-233X 1988 [Refereed][Not invited]
     
    Among various divalent metal ions, calcium has been found to be adsorbed tightly onto carboxymethylated chitin. The adsorption was completed not only by induced carboxyl groups but also by the support of acetamide, as well as primary and secondary hydroxyl groups. Although the adsorption capacity for transition metal ions was enhanced appreciably by regeneration into fibrous form, only that of calcium ion, among alkali-earth metals, was at the same level as that of transition metals. Since little effect was shown on the adsorption of phenylalanine by the blocking of a-amino and a-carboxyl groups of L-Phe, and since D-Phe was so a little adsorbed, the chiral specific adsorption of phenylalanine might be supported by mediation of calcium ion and by the contribution of hydrophobicity of the P-phenyl group. © 1988, Taylor & Francis Group, LLC. All rights reserved.

MISC

  • 榊原義道, 長田晃汰, 浦木康光, 生方信, 重冨顕吾  日本木材学会大会研究発表要旨集(完全版)(CD-ROM)  70th-  2020
  • S1+G型の引張あて材木部繊維におけるリグニンと非セルロース性多糖類、AGPの分布．
    吉永 新, 粟野達也, 幸田圭一, 玉井 裕, 浦木康光, 高部圭司  第69回日本木材学会大会講演要旨集  2019/03  [Not refereed][Not invited]
  • コニフェリルアルコールの脱水素重合に及ぼすヘミセルロースの効果．
    松尾朱実, 古川貴大, 玉井 裕, 幸田圭一, 浦木康光, 吉永 新, 高部圭司  第68回日本木材学会大会講演要旨集  2018/03  [Not refereed][Not invited]
  • 樹木組織中での安定同位体標識モノリグノール類の移動～同位体顕微鏡による可視化～
    小川真由, 幸田圭一, 重富顕吾, 坂本直哉, 高部圭司, 吉永 新, 浦木康光  第67回日本木材学会大会講演要旨集  129  -129  2017/03  [Not refereed][Not invited]
  • CHENG Ningning, 山本陽子, 幸田圭一, 浦木康光, 五十嵐圭日子  セルロース学会年次大会講演要旨集  23rd-  2016
  • Yasumitsu Uraki, Qiang Li, Teuku Bardant, Keiichi Koda  ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY  249-  2015/03  [Not refereed][Not invited]
  • Yasumitsu Uraki, Keiichi Koda  Journal of Wood Science  61-  (3)  447  -454  2015  [Refereed][Invited]
  • 山本陽子, CHENG Ningning, WINARNI Ina, 五十嵐圭日子, 幸田圭一, 浦木康光  セルロース学会年次大会講演要旨集  21st-  2014
  • 山本陽子, CHENG Ningning, 幸田圭一, 浦木康光, 五十嵐圭日子  日本木材学会北海道支部講演集(Web)  (46)  2014
  • 山本陽子, 及川千皓, 幸田圭一, 浦木康光, 五十嵐圭日子  セルロース学会年次大会講演要旨集  20th-  2013
  • Yasumitsu Uraki, Keiichi Koda, Tatsuhiko Yamada  機能材料  32-  (2)  42  -47  2012  [Not refereed][Invited]
  • Yasumitsu Uraki, Keiichi Koda  Journal of the society of materials science, Japan  61-  (10)  867  -871  2012  [Refereed][Not invited]
  • Masato Ogawa, Teuku B. Bardant, Yasutaka Sasaki, Yutaka Tamai, Seiichi Tokura, Yasumits Uraki  BIORESOURCES  7-  (1)  236  -245  2012  [Not refereed][Not invited]
     
    Activated carbons (ACs) were prepared from biomass of Borneo island (wood charcoal, peat, and coconut husk) by using an electricity-free furnace, of which the energy source was exclusively wood charcoal. This furnace was comprised of two parts, an inner vessel equipped with water inlet for steam activation and an outer shell as a heating part for the inner vessel. The inside temperature of the inner vessel was able to reach over 1000 degrees C. Peat and wood charcoal were converted to AC by carbonization followed by steam activation, and the specific BET surface areas of resultant ACs were 889 m(2)/g and 749 m(2)/g, respectively. A mobile apparatus for water purification was newly designed and fabricated with the resultant AC, together with a white quartz sand, which is called keranggas in Kalimantan. The CODOH of both polluted creek water by the University of Palangka Raya and Kahayan River water were remarkably decreased by the purification with the designed apparatus from 20.0 mgO/L to 0.93 mgO/L, and 18.2 mgO/L to 0.74 mgO/L, respectively. Thus, the newly designed furnace and purification apparatus were shown to be highly effective tools to produce a promising agent for water purification and to produce clarified water without use of electricity, respectively.
  • Yasumitsu Uraki, Yutaka Tamai, Takuro Hirai, Keiichi Koda, Hiroshi Yabu, Masatsugu Shimomura  MATERIALS SCIENCE & ENGINEERING C-MATERIALS FOR BIOLOGICAL APPLICATIONS  31-  (6)  1201  -1208  2011/08  [Not refereed][Not invited]
     
    Wood cell wall, composed of polysaccharides (cellulose and hemicelluloses) and an aromatic polymer (lignin), exhibits a honeycomb-like alignment. We have been making attempts to fabricate cellulose-based materials to reconstruct these wood components artificially, mimicking their formation processes. Those attempts are aiming not only at better understanding of the significance and the function of each wood component, but also at providing a novel, biomass-based polymer material with functionality. This article outlines a protocol to prepare honeycomb-patterned cellulose films with two different polymorphisms, carrying different pore sizes, as a basic framework of the artificial cell wall structure. It also illustrates the effect of the presence of hemicellulose and lignin on the physical property of the honeycomb-patterned cellulose films, when they were adsorbed onto the films. (C) 2010 Elsevier B.V. All rights reserved.
  • Yasumitsu Uraki, Chihiro Oikawa, Tomohiro Aso, Keiichi Koda, Tatsuhiko Yamada  ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY  241-  2011/03  [Not refereed][Not invited]
  • 及川千皓, イナウィナルニ, 幸田圭一, 浦木康光, 山田竜彦, 野尻昌信, 五十嵐圭日子  高分子学会北海道支部研究発表会講演要旨集  45th-  2011
  • 及川千皓, WINARNI Ina, 幸田圭一, 浦木康光, 山田竜彦, 野尻昌信, 五十嵐圭日子  セルロース学会年次大会講演要旨集  18th-  2011
  • 及川千皓, イナウィナルニ, 幸田圭一, 浦木康光, 山田竜彦, 野尻昌信, 五十嵐圭日子  日本木材学会北海道支部講演集(Web)  (43)  2011
  • 田崎裕佳, テウク ベルナバルダント, 浦木康光, 幸田圭一, 藪浩, 下村政嗣  高分子学会北海道支部研究発表会講演要旨集  45th-  2011
  • 田崎裕佳, BARDANT Teuku Berna, 浦木康光, 幸田圭一, 平井悠司, 藪浩, 下村政嗣  セルロース学会年次大会講演要旨集  18th-  2011
  • Yasumitsu Uraki, Harumi Homma, Chihiro Oikawa, Tomohiro Aso, Keiichi Koda  16TH INTERNATIONAL SYMPOSIUM ON WOOD, FIBER AND PULPING CHEMISTRY, PROCEEDINGS, VOLS I & II  165  -169  2011  [Not refereed][Not invited]
     
    We have developed a conversion method of isolated lignins to amphiphiles with three polyethylene glycol (PEG) analogues bearing epoxy groups, termed as PEGDE, EPEG and DAEO. These lignin-based amphiphiles showed significant surface activity. DAEO-derivative revealed the highest activity as comparable to Triton X-100, commercially available nonionic surfactant. We found another useful application of these lignin-based amphiphiles in addition to its utilization as a surfactant. When the amphipiles were added to pulp suspension in a buffered solution together with cellulase, the enzymatic saccharification yields were significantly improved and residual cellulase activity after the saccharification was maintained at higher levels than that without the amphiphiles. EPEG-derivative indicated the highest residual activity. These results suggest that the lignin-based amphiphiles can be used as a cellulase-aid agent, leading to reduction of saccharification cost. EPEG and DAEO-derivatives are also found to act as a cement admixture, which was known to reduce the amount of water used for well dispersing cement, and was very often produced from lignosulfates. These derivatives showed a superior dispersibility for cement to lignosulfates in spite of the fact that it is a nonionic surfactant. In addition, such the derivatives could be prepared directly from black liquor of kraft pulping by one step reaction without isolation of kraft lignin from the black liquor. Thus, a new type cement dispersant or admixture, as well as cellulase-aid agent, was readily prepared from isolated lignins, such as kraft lignin and organosolv lignins, by our developed modification method-with PEG analogues.
  • ホットメルトするリグニン
    ホットメルト材料および装置、製品の最新技術と使い方ノウハウ  78  -82  2011  [Not refereed][Not invited]
  • Keiichi Koda, Satoshi Kubo, Yasumitsu Uraki  ACS Symposium Series  1067-  261  -277  2011  [Not refereed][Not invited]
     
    Development of low-cost, value-added bio-materials from technical lignins is essential in terms of complete utilization of woody biomass components (biorefining). A simply designed chemical modification may provide technical lignins with some unique properties: thermal fusibility, thermal moldability, amphiphilicity, and miscibility with synthetic polymers. Here, the fundamental characteristics of technical lignins are first overviewed. Second, recent progress in chemical modification of technical lignins for industrial application is reviewed. Finally, newly developed lignin-containing materials with functionality are discussed. © 2011 American Chemical Society.
  • URAKI Yasumitsu  Journal of the Surface Science Society of Japan  31-  (6)  301  -306  2010/06/10
  • 及川千皓, 幸田圭一, 浦木康光, 山田竜彦, 野尻昌信, 五十嵐圭日子  セルロース学会年次大会講演要旨集  17th-  2010
  • 田崎裕佳, 浦木康光, 幸田圭一, 山本貞明, 藪浩, 下村政嗣  セルロース学会年次大会講演要旨集  17th-  2010
  • 浦木康光, 田崎裕佳, 玉井裕, 山本貞明, 藪浩, 下村政嗣  高分子学会予稿集(CD-ROM)  59-  (2 Disk1)  2010
  • Yasumitsu Uraki, Chinatsu Matsumoto, Takuro Hirai, Yutaka Tamai, Makiko Enoki, Hiroshi Yabu, Masaru Tanaka, Masatsugu Shimomura  JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY  30-  (4)  348  -359  2010  [Not refereed][Not invited]
     
    We have already fabricated honeycomb-patterned cellulosic films with cellulose I and II polymorphisms as a basal framework in order to create an artificial woody cell wall.[1,2] The adsorption of an isolated lignin, acetic acid lignin (AL), was attempted onto the honeycomb films not only to develop materials further mimicking the cell wall but also to elucidate the mechanical effect of isolated lignin on the tensile strength of the cellulosic architecture. The tensile strengths of honeycomb-patterned cellulosic films were improved by the AL adsorption. Although the cellulosic films without lignin weakened under high moisture content conditions as compared with those under the low content conditions, the lignin-adsorbed cellulosic film maintained significant tensile strength even under the high content conditions. This result suggests that lignin contributes to reinforce the mechanical strength of cellulose framework, in particular high moisture conditions.
  • Yuka Tasaki, Yasumitsu Uraki, Keiichi Koda, Sadaaki Yamamoto, Hiroshi Yabu, Masatsugu Shimomura  RESEARCH PROGRESS IN PAPER INDUSTRY AND BIOREFINERY (4TH ISETPP), VOLS 1-3  3-  1465  -1468  2010  [Not refereed][Not invited]
     
    Honeycomb-patterned cellulose films were prepared, and coated with arabinogalactan, a larch hemicellulose. An application of the hemicellulose-coated, honeycomb-patterned cellulose films was proposed. First, we attempted to control the pore sizes of honeycomb-patterned bacterial cellulose (HPBC) films. HPBC films with pore sizes of 10, 15, and 20 mu m were successfully fabricated, but the one with a pore size of 5 mu m was not. Second, we evaluated the applicability of the arabinogalactan-coated, honeycomb-patterned regenerated cellulose (HPRC) films to scaffolds for hepatocyte culture. It was observed that the arabinogalactan-coated HPRC films had a unique adhesion of hepatocyte: formation of spheroid-like structure and insertion of individual globular cells each in the honeycomb pores.
  • Chihiro Oikawa, Keiichi Koda, Yasumitsu Uraki, Masanobu Nojiri, Tatsuhiko Yamada, Kiyohiko Igarashi  RESEARCH PROGRESS IN PAPER INDUSTRY AND BIOREFINERY (4TH ISETPP), VOLS 1-3  2-  1306  -1309  2010  [Not refereed][Not invited]
     
    An effective cellulase-aid agent has to be developed to establish an efficient saccharification system for bioethanol production from huge piles of unused, lignocellulosic biomass. We have successfully developed some types of lignin derivatives that enhance the efficiency of enzymatic hydrolysis of unbleached pulp with cellulase and help to maintain its original activity after repeated use. These cellulase-aid agents were prepared by the conversion of acetic acid lignin into amphiphilic derivatives with polyethylene glycol-related compounds.
  • Yasumitsu Uraki, Keiichi Koda, Takao Kishimoto, Satoshi Kubo  RESEARCH PROGRESS IN PAPER INDUSTRY AND BIOREFINERY (4TH ISETPP), VOLS 1-3  1-  315  -318  2010  [Not refereed][Not invited]
     
    We have first found that hardwood acetic acid lignin (HAL), one of organosolv lignins, had fusibility, which had never reported for other isolated lignins. HAL can be transformed into fibers by melt spinning, and then carbon fibers and activated carbon fibers by heat treatments. Kubo and his colleagues successfully prepared fibers by melt spinning from a hardwood organosolv lignin and a hardwood kraft lignin. The moldability of these lignins was attributed to fusibility of isolated lignins. However, the relationship between the presence of beta-O-4 bond, the major interunitary linkage of lignin, and its fusibility was not elucidated. We investigated the relationship, using artificially synthesized lignin polymers consisting exclusively of beta-O-4 bond having phenylpropane guaiacyl moiety. As a result, the model polymer was not transformed into a molten state, although it showed a glass transition. It was found, from FT-IR measurement with variable temperature mode, that its molecular motion was suppressed by the formation of intermolecular hydrogen bonding of a primary hydroxyl group at gamma-position. Therefore, the fusibility of organosolv lignins was attributed to the modification of primary hydroxyl group with the cooking solvents used for the pulping processes.
  • Teuku Beuna Bardant, Chihiro Oikawa, Masanobu Nojiri, Keiichi Koda, Yasumitsu Uraki, Yanni Sudiyani, Tatsuhiko Yamada  Mokuzai Gakkaishi/Journal of the Japan Wood Research Society  56-  (6)  420  -426  2010  [Not refereed][Not invited]
     
    A huge amount of lignocellulosic wastes are disposed on an industrial scale as unused biomass both in Japan and in Southeast Asia including forest thinnings of Japanese cedar wood and empty fruit bunches (EFB) of the oil palm tree. Supposing the production of platform compounds from such unused biomass through enzymatic saccharification, we have developed a cellulase-aid agent by the conversion of acetic acid lignin into an amphiphilic derivative (PE-AL). EFB pulps with 10% and 12% residual lignin and cedar pulp with 11% residual lignin were prepared by kraft and soda pulping processes, respectively, as a pretreatment of enzymatic saccharification. An addition of PE-AL significantly improved the saccharification yield of the cedar pulp, while it improved those of EFB pulps dramatically. After the enzymatic saccharification, the cellulase activity remained in the presence of PEAL, although no activity was detected in the absence of PE-AL. © 2010, The Japan Wood Research Society. All rights reserved.
  • Takao Kishimoto, Wakako Chiba, Kaori Saito, Kazuhiko Fukushima, Yasumitsu Uraki, Makoto Ubukata  JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY  58-  (2)  895  -901  2010/01  [Not refereed][Not invited]
     
    Several kinds of natural woods and isolated lignins with various syringyl to guaiacyl (S/G) ratios were subjected to thioacidolysis followed by Raney nickel desulfuration to elucidate the relationships between the S/G ratio and the interunit linkage types of lignin. Furthermore, enzymatic dehydrogenation polymers (DHP) were produced by the Zutropf (gradual monolignol addition) method from mixtures of various ratios of coniferyl alcohol and sinapyl alcohol. The analysis of DHPs and natural wood lignins exhibited basically a similar tendency. The existence of both syringyl and guaiacyl units is effective for producing higher amounts of beta-O-4 and 4-O-5 structures, but it lowers the total amount of cinnamyl alcohol and aldehyde end groups. The relative frequency of the beta-beta structure increased, whereas that of beta-5 and 5-5 structures decreased with increasing syringyl units.
  • Harumi Homma, Satoshi Kubo, Tatsuhiko Yamada, Keiichi Koda, Yasuyuki Matsushita, Yasumitsu Uraki  JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY  30-  (2)  164  -174  2010  [Not refereed][Not invited]
     
    To make use of technical lignins as a nonionic polymeric surfactant, we have already reported the modification of acetic acid lignin (AL) to amphiphilic derivatives by polyoxyethylation using two types of polyethylene glycol (PEG) with diglycidyl (PEGDE) and monoglycidyl (EPEG) groups.[1] Kraft lignin (KL) was converted to amphiphiles in a similar manner. The resultant KL derivatives also indicated high surface activity. Polyethylene glycol with long alkyl chain was introduced to AL, KL, and lignosulfonate (LS) to prepare surfactants of high performance, using dodecyloxy-polyethylene glycol glycidyl ether (DAEO). The resultant DAEO-derivatives showed lower critical micelle concentration by 2-4 orders of magnitude than the corresponding PEGDE- and EPEG-derivatives. The DAEO-derivatives from LS showed better dispersibility for gypsum paste, one of cement components, than LS.
  • Teuku Beuna Bardant, Chihiro Oikawa, Masanobu Nojiri, Keiichi Koda, Yanni Sudiyani, Tatsuhiko Yamada, Yasumitsu Uraki  MOKUZAI GAKKAISHI  56-  (6)  420  -426  2010  [Not refereed][Not invited]
     
    A huge amount of lignocellulosic wastes are disposed on an industrial scale as unused biomass both in Japan and in Southeast Asia : including forest thinnings of Japanese cedar wood and empty fruit bunches (EFB) of the oil palm tree. Supposing the production of platform compounds from such unused biomass through enzymatic saccharification, we have developed a cellulase-aid agent by the conversion of acetic acid lignin into an amphiphilic derivative (PE-AL). EFB pulps with 1096 and 12% residual lignin and cedar pulp with 11% residual lignin were prepared by kraft and soda pulping processes, respectively, as a pretreatment of enzymatic saccharification. An addition of PE-AL significantly improved the saccharification yield of the cedar pulp, while it improved those of EFB pulps dramatically. After the enzymatic saccharification, the cellulase activity remained in the presence of PEAL, although no activity was detected in the absence of PE-AL.
  • Takao Kishimoto, Yasumitsu Uraki, Makoto Ubukata, Masahiro Hamada, Noriyuki Nakajima  ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY  237-  2009/03  [Not refereed][Not invited]
  • Yasumitsu Uraki, Yutaka Tamai, Masato Ogawa, Sampang Gaman, Seiichi Tokura  BIORESOURCES  4-  (1)  205  -213  2009/02  [Not refereed][Not invited]
     
    Peat with an approximate 60% carbon content collected in the suburbs of Palangka Raya, Indonesia, was carbonized, followed by activation with steam in an electric furnace. The resultant activated carbon (AC) had ca. 900 m(2)/g of BET surface area and 1000 mg/g of iodine adsorption. This performance implies that this AC can be used as an adsorbent for environmental purification. We had a carbonizing furnace manufactured in Palangka Raya, which did not require electric power. Some AC having 350 mg/g of iodine adsorption was obtained by using this furnace. Although the adsorption ability was much lower than that of commercially available AC, the AC achieved significant decoloration and decrease in chemical oxygen demand of polluted river water. Thus, this article demonstrated the potential of tropical peat soil as a source of AC.
  • 浦木康光, 玉井裕, 平井卓郎, 藪浩, 田中賢, 下村政嗣  高分子学会予稿集(CD-ROM)  58-  (2 Disk1)  2009
  • CRYSTALLINITY OF POLYETHYLENE GLYCOL CHAINS ANCHORED ON LIGNIN MOLECULES
    15th International Symposium of Wood, Fiber and Pulping Chemistry  P-170  2009  [Not refereed][Not invited]
  • CONVERSION OF ACETIC ACID LIGNIN TO A NONIONIC POLYMERIC SURFACTANT
    15th International Symposium of Wood, Fiber and Pulping Chemistry  P-163  2009  [Not refereed][Not invited]
  • CLEAVAGE OF ETHEREAL BONDS IN LIGNIN STRUCTURE WITH ALUMINIUM IODIDE (III) -FORMATION OF CATECHOL MOIETIES FROM GUAIACYL UNITS
    15th International Symposium of Wood, Fiber and Pulping Chemistry  P-042  2009  [Not refereed][Not invited]
  • INFLUENCE OF SYRINGYL-TOGUAIACYL RATIO ON THE STRUCTURE OF LIGNIN
    15th International Symposium of Wood, Fiber and Pulping Chemistry  P-002  2009  [Not refereed][Not invited]
  • CREATION OF ARTIFICIAL CELL WALL BY USING HONEYCOMB-PATTERNED CELLULOSE.
    Proceedings of International Conference on Pulping, papermaking and Biotechnology  O-054  2009  [Not refereed][Not invited]
  • Yoshie Kanazawa, Takao Kishimoto, Keiichi Koda, Kazuhiko Fukushima, Yasumitsu Uraki  JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY  29-  (2)  178  -190  2009  [Not refereed][Not invited]
     
    Dimeric lignin model compounds with non-phenolic and phenolic moieties and a -O-4 type artificial lignin polymer were subjected to thioacidolysis to evaluate the reaction efficiency of thioacidolysis for cleavage of -O-4 interunitary linkage. The obtained yields of thioethylated monomeric products from the dimeric lignin model compounds reached nearly 100% under the conventional condition, whereas that from the artificial lignin polymer was as low as 74%. Neither prolonged reaction time nor increased concentration of ethanethiol (the thioacidolysis reagent) enhanced the resulting monomer yields from the polymer (69-79%). Thioacidolysis of the lignin model compounds followed by HPSEC analysis also showed the dimeric model compounds were degraded almost quantitatively, but that the artificial lignin polymer was not. Thioacidolysis followed by desulfurization gave at least one dimeric product resulting from incomplete -O-4 cleavage at significant yield. These results suggested the conventional thioacidolysis could not achieve quantitative cleavage of -O-4 linkages in lignin macromolecules.
  • Takao Kishimoto, Yasumitsu Uraki, Makoto Ubukata  ORGANIC & BIOMOLECULAR CHEMISTRY  6-  (16)  2982  -2987  2008/08  [Not refereed][Not invited]
     
    We describe the synthesis and NMR spectroscopic analysis of three artificial lignin polymers containing only the beta-O-4 substructure: syringyl-type homopolymer, p-hydroxyphenyl-type homopolymer and guaiacyl/syringyl-type heteropolymer. Using gel permeation chromatography, the weight-average degree of polymerization (DPw) of the three polymers was determined as 19.2. 38.6, and 13.9, respectively. The polymers were prepared based on the synthetic methodology of guaiacyl-type homopolymer, and were fully characterized using H-1-, C-13-, and H-1-C-13 NMR spectroscopy of the acetylated and non-acetylated forms. The spectra of guaiacyl/syringyl-type heteropolymers were in good agreement with those of the beta-O-4 substructure of milled wood lignin obtained from the hardwood of Japanese white birch.
  • Md. Ibrahim H. Mondal, Yasumitsu Uraki, Makoto Ubukata, Koki Itoyama  CELLULOSE  15-  (4)  581  -592  2008/08  [Not refereed][Not invited]
     
    The influence of treating cotton fibres with several amines on the mechanical properties, moisture sorption ability before and after graft polymerization, and on graft yields for various water-soluble and water-insoluble vinyl monomers were analysed. As compared to water, the treatment with amines, ethylenediamine (EDA) in particular, resulted in a decrease in the crystallinity and tensile strength of the cotton fibres, and an increase in the moisture sorption. The graft yields of amine-treated cotton fibres using water-soluble monomers, acrylic acid (AA), methacrylic acid (MAA) and acrylamide (AM) were greater than those observed for water-treated cotton fibres, whereas the graft yields using water-insoluble monomers, methyl acrylate (MA), methyl methacrylate (MMA) and vinyl acetate (VA) were lower. The moisture sorption ability was improved by the graft polymerization with water-soluble monomers. The improvement was enhanced for MA and MAA by treatment with sodium hydroxide to form the corresponding sodium carboxylate derivatives. The tensile strength of EDA-treated cotton was slightly reduced by grafting, while that of the water-activated cotton yarn was barely changed. These results suggest that the graft polymerization of amine-treated cotton fibres with certain vinyl monomers increased the moisture sorption ability without resulting in increased fibre rigidity.
  • Makiko Enoki, Michisuke Sato, Kodai Kaneda, Ryota Sekiyama, Akiko Nakagawa, Yasumitsu Uraki, Haruyuki Kanehiro  Nippon Suisan Gakkaishi (Japanese Edition)  74-  (4)  688  -693  2008/07  [Not refereed][Not invited]
     
    Sea algal paste was obtained by soaking brown alga in sodium carbonate solution and was found to have a flocculating effect on muddy water in the presence of calcium chloride as a cross linking agent. This technique does not involve the extraction of alginic acid and production of secondary waste. The sea alga paste obtained by soaking in sodium carbonate solution for five minutes at 70°C demonstrated an excellent flocculating effect, which did not depend on the density of muddy water. Stirring time after mixing all ingredients was found to affect the flocculation. Furthermore, the amount of sea alga paste and calcium chloride also influenced the coagulating effect.
  • Makiko Enoki, Michisuke Sato, Kodai Kaneda, Ryota Sekiyama, Akiko Nakagawa, Yasumitsu Uraki, Haruyuki Kanehiro  NIPPON SUISAN GAKKAISHI  74-  (4)  688  -693  2008/07  [Not refereed][Not invited]
     
    Sea algal paste was obtained by soaking brown alga in sodium carbonate solution and was found to have a flocculating effect on muddy water in the presence of calcium chloride as a cross linking agent. This technique does not involve the extraction of alginic acid and production of secondary waste. The sea alga paste obtained by soaking in sodium carbonate solution for five minutes at 70 degrees C demonstrated an excellent flocculating effect, which did not depend on the density of muddy water. Stirring time after mixing all ingredients was found to affect the flocculation. Furthermore, the amount of sea alga paste and calcium chloride also influenced the coagulating effect.
  • 浦木康光, 生方信, MONDAL Md, Ibrahim H, 糸山光紀  繊維学会予稿集  63-  (1/2)  110  2008/06/18  [Not refereed][Not invited]
  • 本間春海, 浦木康光, 生方信, 久保智史, 山田竜彦  繊維学会予稿集  63-  (1/2)  128  2008/06/18  [Not refereed][Not invited]
  • Yasumitsu Uraki, Md Mondal H. Ibrahim, Koki Itoyama, Makoto Ubukata  ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY  235-  2008/04  [Not refereed][Not invited]
  • 三橋進也, 岸本崇生, 浦木康光, 生方信  日本農芸化学会大会講演要旨集  2008-  168  2008/03/05  [Not refereed][Not invited]
  • Shinya Mitsuhashi, Takao Kishimoto, Yasumitsu Uraki, Takashi Okamoto, Makoto Ubukata  BIOORGANIC & MEDICINAL CHEMISTRY  16-  (5)  2645  -2650  2008/03  [Not refereed][Not invited]
     
    Human immunodeficiency virus type 1 (HIV-1) is a cytopathic retrovirus and the primary etiological agent of acquired immunodeficiency syndrome (AIDS) and related disorders. In cells chronically infected with HIV-1, nuclear factor-kappa B (NF-kappa B) activation by external stimuli such as tumor necrosis factor alpha (TNF alpha) augments replication of HIV-1. NF-kappa B involves in many diseases such as inflammation, cancer, and. Crohn's disease. In this paper, we exhibit that (i) HIV-1 gene expression was inhibited by lignin, (ii) fraction of small molecular mass in HBS lignin (less than 0.5 kDa) had stronger inhibitory effects than large molecular mass (more than 1.3 kDa), (iii) lignin also inhibited activation of NF-kappa B induced by TNF alpha, (iv) among six lignin dimer-like compounds, compound 6 containing beta-5 bond has more potent inhibitory activity than compounds 1, 2, 3, 4 and 5, which contain beta-1, beta-O-4, 5-5, or beta-beta structural units. These results suggested that small molecules of lignin inhibit HIV-1 replication through suppression of HIV-1 transcription from LTR including activation via NF-kappa B. Low molecular lignin may be a beneficial material or drug leads as a new class for AIDS and NF-kappa B-related diseases. (C) 2008 Published by Elsevier Ltd.
  • 松本千夏, 浦木康光, 平井卓郎, 生方信, 藪浩, 田中賢, 下村政嗣  高分子学会北海道支部研究発表会講演要旨集  42nd-  15  2008/01/29  [Not refereed][Not invited]
  • 本間春海, 浦木康光, 生方信, 山田竜彦, 久保智史  日本木材学会大会研究発表要旨集(完全版)(CD-ROM)  58th-  ROMBUNNO.L19-0945  2008  [Not refereed][Not invited]
  • 松本千夏, 浦木康光, 平井卓郎, 玉井裕, 生方信  日本木材学会大会研究発表要旨集(完全版)(CD-ROM)  58th-  ROMBUNNO.K18-1645  2008  [Not refereed][Not invited]
  • Polymerization of coniferyl alcohol by chain reaction. Another reaction for lignin formation.
    Cellulose Chemistry and Technology  41-  (9-10)  505  -509  2008  [Not refereed][Not invited]
  • Harumi Homma, Satoshi Kubo, Tatsuhiko Yamada, Yasuyuki Matsushita, Yasumitsu Uraki  JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY  28-  (4)  270  -282  2008  [Not refereed][Not invited]
     
    Acetic acid lignin (AL), one of the organosolv lignins, was modified by polyoxyethylation using commercially available polyethylene glycol diglycidylethers (PEGDE) having various chain lengths in order to generate novel nonionic polymeric surfactants. AL could be converted to the amphiphile by modifying with PEGDE (PEGDE-AL) having more than 9 of the ethylene oxide (EO) repeating units. Although the surface activities of PEG and AL were very limited, PEGDE-AL did strongly depress surface tension of water, and showed clear critical micelle concentrations (CMC). The CMC value of PEGDE-AL could be comparable to a commercial anionic lignin surfactant, lignosulfonate. The surface activity of AL amphiphile was further improved by modification with monoepoxides, ethoxy-(2-hydroxy)-propoxy-polyethylene glycol glycidylether (EPEGGE). The surface tension of water was depressed by the addition of the EPEGGE-AL to the same level as Triton X-100, which is a commercial PEG-based nonionic surfactant, although there is still room for improvement in CMC value. The hydrophile-lipophile balance (HLB) of these AL amphiphiles was in the range of 11-14, and significant biodegradation was observed. These results suggest that the AL amphiphiles can be used as emulsifier and detergent.
  • Takao Kishimoto, Yasumitsu Uraki, Makoto Ubukata  JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY  28-  (2)  97  -105  2008  [Not refereed][Not invited]
     
    Guaiacyl, syringyl, and p-hydroxyphenyl-type bromoacetophenone derivatives were synthesized as the starting materials for beta -O-4 type artificial lignin polymers. They were prepared from 4-hydroxyacetophenone instead of 4-hydroxybenzaldehyde, which was used in the previous investigations. The new route required 4 reaction steps. Overall yields of the monomers were 60, 79, and 68%, respectively.
  • 岸本崇生, 浦木康光, 生方信  リグニン討論会講演集  52nd-  86  -89  2007/10/31  [Not refereed][Not invited]
  • 金澤香枝, 浦木康光, 生方信, 岸本崇生  リグニン討論会講演集  52nd-  90  -93  2007/10/31  [Not refereed][Not invited]
  • 鈴木啓介, 浦木康光, 生方信  リグニン討論会講演集  52nd-  152  -153  2007/10/31  [Not refereed][Not invited]
  • 杉山祐介, 浦木康光, 生方信, 岸本崇生  日本木材学会北海道支部講演集  (39)  61  -64  2007/10/22  [Not refereed][Not invited]
  • 松本千夏, 浦木康光, 生方信, 玉井裕, 平井卓郎, 藪浩, 田中賢, 下村政嗣  日本木材学会北海道支部講演集  (39)  31  -34  2007/10/22  [Not refereed][Not invited]
  • 岸本崇生, 浦木康光, 生方信  天然有機化合物討論会講演要旨集  49th-  575  -580  2007/08/24  [Not refereed][Not invited]
  • 松本千夏, 浦木康光, 生方信, 平井卓郎, 藪浩, 田中賢, 下村政嗣  セルロース学会年次大会講演要旨集  14th-  77  2007/07/15  [Not refereed][Not invited]
  • Yasumitsu Uraki, Junji Nemoto, Hiroyuki Otsuka, Yutaka Tamai, Junji Sugiyama, Takao Kishimoto, Makoto Ubukata, Hiroshi Yabu, Masaru Tanaka, Masatsugu Shimomura  CARBOHYDRATE POLYMERS  69-  (1)  1  -6  2007/05  [Not refereed][Not invited]
     
    Bacterial cellulose (BC)-producing bacterium, Gluconacetobacter xylinus (ATCC53582), was found to move along linear microgrooves of a stripe-patterned cellulosic scaffold. On the basis of this finding, fabrication of honeycomb-patterned BC was attempted by controlling the bacterial movement using a agarose film scaffold with honeycomb-patterned grooves (concave type). The patterned agarose film was prepared by three steps. The first was transcription of a honeycomb-patterned polycaprolactone film template with polydimethyl siloxane. When the bacteria were cultured on the scaffold under atmospheric conditions, only bacterial proliferation was observed. Honeycomb-patterned BC was obtained when cultured under a humid CO2 atmosphere. Electron diffraction and polarized microscopic observation showed that the patterned BC comprised of the well defined cellulose lot microfibrils. As another attempt to fabricate honeycomb-patterned BC, the bacteria were cultured on the patterned cellulose and agarose film with convex type of honeycomb. This culture yielded no honeycomb-patterned BC. Therefore, concave type honeycomb scaffold is more suitable to fabricate honeycomb-patterned BC. (c) 2006 Elsevier Ltd. All rights reserved.
  • 岸本崇生, 浦木康光, 生方信  日本農芸化学会大会講演要旨集  2007-  105  2007/03/05  [Not refereed][Not invited]
  • 鈴木啓介, 浦木康光, 岸本崇生, 生方信  高分子学会北海道支部研究発表会講演要旨集  41st-  38  2007/02/06  [Not refereed][Not invited]
  • Yasumitsu Uraki  SEN-I GAKKAISHI  63-  (1)  P18  -P22  2007/01  [Not refereed][Not invited]
  • 杉山祐介, 浦木康光, 生方信, 岸本崇生  日本木材学会大会研究発表要旨集(完全版)(CD-ROM)  57th-  L08-0945  2007  [Not refereed][Not invited]
  • Yasumitsu Uraki, Atsushi Nakamura, Takao Kishimoto, Makoto Ubukata  JOURNAL OF WOOD CHEMISTRY AND TECHNOLOGY  27-  (1)  9  -21  2007  [Not refereed][Not invited]
     
    Interactions of hemicelluloses, xylan and glucomannan, with monolignols, coniferyl alcohol and sinapyl alcohol, and their glucosides, coniferin and syringin, were investigated by surface plasmon resonance analysis. Hemicelluloses with different aldehyde contents, prepared by sodium periodate oxidation, were immobilized onto carboxymethyl-dextran-coated gold plates by reductive amination. The interaction of the hemicelluloses with monolignols was evaluated as weight gain of the hemicelluloses at neutral pH. Both hemicelluloses adsorbed the monolignols in much larger amounts than the corresponding glucosides. The adsorption tendency was independent of aldehyde content. These results suggest the hemicelluloses have higher affinities to the aglycons than the glucosides. Thus, the interactions of the hemicelluloses with monolignols are primarily the result of hydrophobic interactions. However, binding constants were not estimated because of the low solubility of the monolignols in the aqueous buffered solution.
  • 千葉和歌子, 岸本崇生, 浦木康光, 生方信, 齋藤香織, 福島和彦  日本木材学会北海道支部講演集  (38)  35  -38  2006/10/31  [Not refereed][Not invited]
  • 杉山祐介, 岸本崇生, 浦木康光, 生方信, 久保智史  日本木材学会北海道支部講演集  (38)  39  -42  2006/10/31  [Not refereed][Not invited]
  • 三橋進也, 岸本崇生, 浦木康光, 生方信  リグニン討論会講演集  51st-  112  -115  2006/10/10  [Not refereed][Not invited]
  • 宮田直紀, 荻野晋一, 浦木康光, 生方信  リグニン討論会講演集  51st-  116  -119  2006/10/10  [Not refereed][Not invited]
  • 岸本崇生, 浦木康光, 生方信  リグニン討論会講演集  51st-  212  -213  2006/10/10  [Not refereed][Not invited]
  • 松本千夏, 浦木康光, 岸本崇生, 生方信, 藪浩, 田中賢, 下村政嗣  セルロース学会年次大会講演要旨集  13th-  32  -33  2006/07/01  [Not refereed][Not invited]
  • Y Uraki, T Imura, T Kishimoto, M Ubukata  CELLULOSE  13-  (3)  225  -234  2006/06  [Not refereed][Not invited]
     
    The lower critical solution temperature (LCST) of hydroxypropylcellulose bearing lignin (HPC-L) prepared from unbleached pulp depends on the amount of residual lignin. An HPC-L gel having thermal properties reflective of original HPC-L was prepared using ethyleneglycol diglycidylether as a crosslinker, as previously reported [Uraki et al. (2004) Carbohydr. Polym. 58:123-130], and the volume transition temperature was detected as an endothermic peak by differential scanning calorimetry (DSC). The adsorption and release behavior of the guest molecules to/from this gel was then examined. When the adsorption of cationic and anionic guests was compared, cationic methylene blue (MB) was adsorbed in larger amounts than anionic methyl orange (MO). In addition, MB adsorption into the HPC-L gel was greater than MB adsorption into the HPC gel prepared from commercially available HPC. This suggests that residual lignin affects the adsorption of organic dyes. Significant differences were not observed with respect to the release of MB from HPC-L at 38 degrees C and lower temperatures. In the adsorption of surfactants, marked adsorption at around the critical micelle concentration of the ionic surfactants and gel swelling were observed. Such swelling did not occur in the aqueous nonionic surfactant solution, although the nonionic surfactant was adsorbed into the gel. Gel swelling may have been caused by the electrostatic repulsion of the ionic surfactants adsorbed onto the polymer chains within the gel structure.
  • Y Uraki, J Nemoto, Y Sano  JOURNAL OF WOOD SCIENCE  52-  (2)  163  -166  2006/04  [Not refereed][Not invited]
     
    We developed a novel method for preparation of microcasts of wood with silicone elastomer (polydimethylsiloxane; PDMS). PDMS was so flexible and elastic that it was possible to isolate the microcasts by simply pulling them out of the mold without digesting the cell wall after the resin was cured for 2 days at room temperature. The casts of some cell wall sculptures, such as spiral thickenings and bordered pits, had high fidelity. By contrast, the casts of distinctly bordered pits and tails of vessel elements were often deformed or broken. Bars of scalariform perforation plates were always torn and remained in the resin casts. The microcast preparation using PDMS is useful for easy investigation of cell wall sculptures. It might be also useful for microfractography of bars of scalariform perforation plates.
  • 岸本崇生, 浦木康光, 生方信  日本農芸化学会大会講演要旨集  2006-  16  2006/03/05  [Not refereed][Not invited]
  • 岸本崇生, 重松幹二, 浦木康光, 生方信  日本木材学会大会研究発表要旨集(完全版)(CD-ROM)  56th-  2006
  • 浦木康光, 松本千夏, 岸本崇生, 生方信, 藪浩, 田中賢, 下村政嗣  日本農芸化学会北海道支部・日本土壌肥料学会北海道支部・日本生物工学会北日本支部・日本応用糖質科学会北海道支部・北海道農芸化学協会合同学術講演会講演要旨  2006-  13  2006  [Not refereed][Not invited]
  • Yasumitsu Uraki, Yuriko Usukura, Takao Kishimoto, Makoto Ubukata  HOLZFORSCHUNG  60-  (6)  659  -664  2006  [Not refereed][Not invited]
     
    A lignin-carbohydrate complex (LCC) fraction isolated from the residue of milled wood lignin extraction of birch was found to form self-aggregates in water. The aggregates had relatively strong hydrophobic domains, comparable to the hydrophobicity of 80% ethanol. Dynamic light scattering analysis showed that the aggregates were transformed into small particles by sonication with a number-average diameter of 43.7 +/- 9.6 nm, and were stable in water. The surface pressure (pi)-surface area (A) profile showed that the LCC also formed a monolayer on the water surface. Based on these results, we suggest that the LCC is amphiphilic in nature, despite its insolubility in low-polarity organic solvents.
  • T Kishimoto, Y Uraki, M Ubukata  ORGANIC & BIOMOLECULAR CHEMISTRY  4-  (7)  1343  -1347  2006  [Not refereed][Not invited]
     
    An artificial lignin polymer containing only the beta-O-4 substructure was synthesized. The procedure consists of two key steps: 1) polycondensation of a brominated monomer by aromatic Williamson reaction; and 2) subsequent reduction of the carbonyl polymer. C-13-NMR and HMQC spectra of the polymer were consistent with beta-O-4 substructures in milled wood lignin isolated from Japanese fir wood. The weight average degree of polymerization (DPw) ranged from 19.5 to 30.6, which is comparable to enzymatically synthesized artificial lignin from p-hydroxycinnamyl alcohols ( dehydrogenation polymer, DHP) and some isolated lignins. Using this new lignin model polymer, it will now be possible to reinvestigate the properties and reactivity of the main lignin structure in terms of its polymeric character.
  • 重冨顕吾, 中村淳, 岸本崇生, 浦木康光, 生方信  日本木材学会北海道支部講演集  (37)  17  -20  2005/10/21  [Not refereed][Not invited]
  • 浦木康光, 井村健, 岸本崇生, 生方信  リグニン討論会講演集  50th-  46  -49  2005/10/07  [Not refereed][Not invited]
  • 生方信, 植木飛鳥, 三橋進也, 岸本崇生, 浦木康光, 藤田進一郎  リグニン討論会講演集  50th-  50  -53  2005/10/07  [Not refereed][Not invited]
  • 岸本崇生, 浦木康光, 生方信  リグニン討論会講演集  50th-  146  -147  2005/10/07  [Not refereed][Not invited]
  • 浦木康光, 大塚裕之, 玉井裕, 佐野雄三, 岸本崇生, 生方信, 杉山淳司, 田中賢, 藪浩, 下村政嗣  セルロース学会年次大会講演要旨集  12th-  89  -90  2005/07/11  [Not refereed][Not invited]
  • 浦木康光, 大塚裕之, 生方信, 薮浩, 田中賢, 下村政嗣  高分子学会予稿集(CD-ROM)  54-  (1 Disk1)  2M14  2005/05/10  [Not refereed][Not invited]
  • 大塚裕之, 浦木康光, 根本純司, 岸本崇生, 生方信, 薮浩, 田中賢, 下村政嗣  日本農芸化学会大会講演要旨集  2005-  159  2005/03/05  [Not refereed][Not invited]
  • 岸本崇生, 浦木康光, 生方信  日本農芸化学会大会講演要旨集  2005-  21  2005/03/05  [Not refereed][Not invited]
  • 臼倉ゆり子, 浦木康光, 植木飛鳥, 岸本崇生, 生方信  日本農芸化学会大会講演要旨集  2005-  194  2005/03/05  [Not refereed][Not invited]
  • 中村淳, 浦木康光, 岸本崇生, 生方信  日本木材学会北海道支部講演集  (37)  2005
  • 中村淳, 浦木康光, 岸本崇生, 生方信  リグニン討論会講演集  50th-  2005
  • Investigation on interaction of hemicelluloses with monolignols using surface plasmon resonance
    Proceedings of 13th International Symposium on Wood, Fiber and Pulping Chemistry  3-  277  -281  2005  [Not refereed][Not invited]
  • Preparation of intelligent gels with a body-temperature response from unbleached acetic acid pulp.
    Proceedings of 13th International Symposium on Wood, Fiber and Pulping Chemistry  2-  545  -551  2005  [Not refereed][Not invited]
  • Preparation and chracterizaton of fiberboards from waste papers bonded by lignin.
    Proceedings of presimposium of 13th International Symposium on Wood, Fiber and Pulping Chemistry  (1)  159  -163  2005  [Not refereed][Not invited]
  • T. Kishimoto, Y. Uraki and M. Ubukata: Easy synthesis of -O-4 type lignin related polymers. Org. Biomol. Chem., 3, 1067-1073 (2005).*
    2005  [Not refereed][Not invited]
  • J. Nemoto, Y. Uraki, T. Kishimoto, Y. Sano, R. Funada, N. Obata, H. Yabu, M. Tanaka, M. Shimomura: Production of mesocopically patterned cellulose film. Bioresource Tech., 96, 1955-1958 (2005).*
    2005  [Not refereed][Not invited]
  • Y Uraki, J Nemoto, K Yanaga, A Koizumi, T Hirai  JOURNAL OF WOOD SCIENCE  51-  (6)  589  -594  2005  [Not refereed][Not invited]
     
    Board-shaped composites with medium density (MDF) were prepared from isolated lignins and waste newspaper, in addition to preparation of the composites with high density (HB). The board properties of both composites concerning bending strength and water resistance were improved by the addition of hardwood acetic acid lignin (HAL). The internal bond strength and water resistance of MDF, in particular the degree of thickness swelling (TS), were also improved by prolonged molding time. Adding inorganic salts contributed to the improvement of TS. The effect depended on the charge of the cation. Considering practical utilization of lignin-based MDF as a structural material, its performance was evaluated by combination of the single-shear test of nailed joints and the modulus of rigidity. As a result, this MDF had sufficient strength to be utilized as an internal shear wall material. Therefore, lignin can be considered as an alternative to conventional adhesives for the production of boards such as HB and MDF.
  • “森林の科学－森林生態系科学入門－”<中村太士、小池孝良編著>
    朝倉書店  2005  [Not refereed][Not invited]
  • Y Uraki, T Imura, T Kishimoto, M Ubukata  CARBOHYDRATE POLYMERS  58-  (2)  123  -130  2004/11  [Not refereed][Not invited]
     
    Hydroxypropylcellulose bearing lignin (HPC-L) prepared from softwood by the atmospheric acetic acid pulping followed by derivatization showed the lower critical solution temperature (LCST) of approximate 38degreesC in 2% aqueous solution, which were 5degrees lower than that of pure HPC with a similar molecular mass to HPC-L. Two types, urethane and epoxy, of chemical gels were prepared from HPC-L and HPC using hexamethylene diisocyanate and polyethylene glycol diglycidyl ether as crosslinkers, respectively. The urethane-type gels from both HPC's have undergone shrinking at less than 20degreesC. This thermoresponse of the gels did not reflect LCST of the sources. Such low temperature shrinking was brought about by the hydrophobicity of crosslinker. On the other hand, the epoxy-type gels showed a very similar volume transition temperature (VTT) upon shrinking to LCST; the epoxy-type HPC-L gel showed VTT at 38degreesC, while the corresponding HPC gel had VTT at 46degreesC. This difference in VTT as well as LCST was attributable to hydrophobicity of lignin dangled to HPC. Thus, the body temperature-responsive gel can be prepared from HPC-L with the water-soluble crosslinker. (C) 2004 Elsevier Ltd. All rights reserved.
  • 井村健, 浦木康光, 岸本崇生, 生方信  日本木材学会北海道支部講演集  (36)  35  -38  2004/10/28  [Not refereed][Not invited]
  • 岸本崇生, 浦木康光, 生方信  リグニン討論会講演集  49th-  21  -24  2004/10/20  [Not refereed][Not invited]
  • 田村裕, 戸倉清一, 山本克憲, 国安春子, 浦木康光, 生方信  高分子学会予稿集(CD-ROM)  53-  (2 Disk1)  2PF160  2004/09/01  [Not refereed][Not invited]
  • 田村裕, 真田陽子, 戸倉清一, 浦木康光, 生方信  セルロース学会年次大会講演要旨集  11th-  9  -10  2004/07/01  [Not refereed][Not invited]
  • 根本純司, 浦木康光, 岸本崇生, 生方信, 薮浩, 田中賢, 下村政嗣  セルロース学会年次大会講演要旨集  11th-  105  2004/07/01  [Not refereed][Not invited]
  • Y Usukura, Y Uraki, T Kishimoto, M Ubukata, T Hiraoki  ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY  227-  U311  -U311  2004/03  [Not refereed][Not invited]
  • 浦木康光, 中村淳, 岸本崇生, 生方信  リグニン討論会講演集  49th-  2004
  • 臼倉ゆり子, 植木飛鳥, 浦木康光, 岸本崇生, 生方信  リグニン討論会講演集  49th-  2004
  • 浦木康光, 井村健, 臼倉ゆり子, 岸本崇生, 生方信  日本学術会議材料研究連合講演会講演論文集  48th-  2004
  • リグニンとセルロース系バイオマスから調製した種々の成形活性炭
    木質炭化学会誌  1-  (1)  23  -29  2004  [Not refereed][Not invited]
  • T Kishimoto, A Ueki, H Takamori, Y Uraki, M Ubukata  HOLZFORSCHUNG  58-  (4)  355  -362  2004  [Not refereed][Not invited]
     
    In order to investigate the delignification mechanism during high-boiling solvent (HBS) pulping, softwood HBS lignin samples from todo fir (Abies sachalinensis) were analyzed by H-1-C-13 correlation NMR spectroscopy (HMQC). Nine lignin model compounds that may represent the substructures in HBS lignin were prepared. The H-1 and C-13 NMR spectral data were compared with HBS lignin samples. The HMQC spectra of HBS lignin samples showed the disappearance of beta-O-4 structures. Introduction of a pulping solvent into lignin was plainly observed with new signals in aliphatic regions. Only the erythro beta-1 structure was detected in softwood milled wood lignin from todo fir by HMQC spectra. The beta-1 structure was very reactive and probably produced the stilbene structure. The beta-beta and beta-5 structures remained in HBS lignin. The 4-O-5 structure was successfully detected by HMQC spectra, and it was found to be stable under the conditions used.
  • T. Imura, Y. Uraki, T. Kishimoto and M. Ubukata: Thermoresponsive gels prepared from hydroxypropylated unbleached pulp. Proceeding of The 2nd International Symposium on Technologies of Pulping, Papermaking and Biotechnology on Fiber Plants, 595-528 (20・・・
    2004  [Not refereed][Not invited]
     
    T. Imura, Y. Uraki, T. Kishimoto and M. Ubukata: Thermoresponsive gels prepared from hydroxypropylated unbleached pulp. Proceeding of The 2nd International Symposium on Technologies of Pulping, Papermaking and Biotechnology on Fiber Plants, 595-528 (2004).
  • A. Nakamura, Y. Uraki, T. Kishimoto and M. Ubukata: Analysis of adsorption behavior of monolignols onto hemicellulose using surface plasmon resonance. Proceeding of The 2nd International Symposium on Technologies of Pulping, Papermaking and Biotechnolo・・・
    2004  [Not refereed][Not invited]
     
    A. Nakamura, Y. Uraki, T. Kishimoto and M. Ubukata: Analysis of adsorption behavior of monolignols onto hemicellulose using surface plasmon resonance. Proceeding of The 2nd International Symposium on Technologies of Pulping, Papermaking and Biotechnology on Fiber Plants, 521-524 (2004).
  • “木質系有機資源の新展開”<舩岡正光監修>
    シーエムシー  2004  [Not refereed][Not invited]
  • H Sato, Y Uraki, T Kishimoto, Y Sano  CELLULOSE  10-  (4)  397  -404  2003/12  [Not refereed][Not invited]
     
    To explore further potential applications of acetic acid pulp, an investigation was conducted to develop a direct method for producing cellulose acetate from wood in combination with atmospheric acetic acid pulping. The process consists of delignification, totally chlorine-free bleaching, and esterification, with the concentrated acetic acid aqueous solution being used as only solvent throughout the process. The acetic acid pulp with kappa number of 30 and ISO brightness of 16 was bleached with 5% ozone on pulp to kappa number of 1.4 and brightness of 61. The resulting bleached pulp was further bleached with peracetic acid to kappa number of less than 1.0 and brightness of 68. The final bleached acetic acid pulp was acetylated with acetic anhydride in the concentrated acetic acid for 45 min to produce cellulose acetate with an apparent degree of substitution (DS) of 2.54. Although the product was lower grade compared with commercially available cellulose diacetate because it was prepared from the chemical pulp but not dissolving pulp, the product was almost soluble in acetone. Eventually, the DS of the acetone-soluble fraction was 2.62. The acetone solubility might be attributed to the original acetic acid pulp that had been partially acetylated during the pulping.
  • 井村健, 浦木康光, 岸本崇生, 生方信  日本木材学会北海道支部講演集  (35)  74  -77  2003/10/15  [Not refereed][Not invited]
  • 高森ひとみ, 岸本崇生, 浦木康光, 生方信  リグニン討論会講演集  48th-  176  -177  2003/10/15  [Not refereed][Not invited]
  • 井村健, 浦木康光, 岸本崇生, 生方信  リグニン討論会講演集  48th-  200  -201  2003/10/15  [Not refereed][Not invited]
  • 高森ひとみ, 岸本崇生, 浦木康光, 生方信  日本木材学会北海道支部講演集  (35)  78  -81  2003/10/15  [Not refereed][Not invited]
  • 根本純司, 浦木康光, 岸本崇生, 生方信, 田中賢, 下村政嗣  日本木材学会北海道支部講演集  (35)  25  -28  2003/10/15  [Not refereed][Not invited]
  • 臼倉ゆり子, 浦木康光, 岸本崇生, 生方信, 平沖敏文, 福島和彦  リグニン討論会講演集  48th-  202  -205  2003/10/15  [Not refereed][Not invited]
  • 岸本崇生, 浦木康光, 生方信  リグニン討論会講演集  48th-  68  -71  2003/10/15  [Not refereed][Not invited]
  • 臼倉ゆり子, 浦木康光, 岸本崇生, 生方信, 加藤俊之, 福島和彦  日本木材学会北海道支部講演集  (35)  70  -73  2003/10/15  [Not refereed][Not invited]
  • 植木飛鳥, 斉藤香織, 福島和彦, 岸本崇生, 浦木康光, 生方信  リグニン討論会講演集  48th-  178  -179  2003/10/15  [Not refereed][Not invited]
  • T. Kishimoto, H. Tsuji, Y. Uraki and Y. Sano: Ozone bleaching of atmospheric acetic acid pulp from Betula platyphylla var. japonica Hara. Holzforschung, 57, 181-188 (2003).*
    2003  [Not refereed][Not invited]
  • Y. Usukura, Y. Uraki, T. Kishimoto and Y. Sano: Characterization of amphiphilic lignin derivative-Formation of Langmuir Blodgett film and Gel. Proceedings of 12th International Symposium on Wood and Pulping Chemistry, vol.1, 329-332 (2003).
    2003  [Not refereed][Not invited]
  • J. Nemoto, Y. Uraki and Y. Sano:Preparation of fiberboards from waste papers and isolated lignins. Proceedings of 12th International Symposium on Wood and Pulping Chemistry, vol.1, 219-222 (2003).
    2003  [Not refereed][Not invited]
  • リグニン-古紙複合物を原料とするボード状成形物の作製とその特性
    木材学会誌  49-  287  -292  2003  [Not refereed][Not invited]
  • S Kubo, Y Uraki, Y Sano  JOURNAL OF WOOD SCIENCE  49-  (2)  188  -192  2003  [Not refereed][Not invited]
     
    Catalytic graphitization of hardwood acetic acid lignin (HAL) with nickel (II) acetate was investigated regarding the production of highly crystalline carbon. Fusibility, one of the unique characteristics of HAL, was preserved with nickel acetate additions up to 0.3% (as the weight of nickel), although the thermal mobility of HAL was depressed by the addition of nickel acetate. An obvious effect of nickel salt as a catalyst on the development of carbon crystallite from HAL was observed for more than 0.2% addition. The development was found to proceed above 850degreesC. All the resulting carbons had turbostratic structure, and the apparent crystallite size (L-c) was increased with increasing amounts of catalyst, as determined by X-ray diffraction. Thus, highly crystalline carbon was produced from HAL by catalytic graphitization without compromising the fusibility of HAL by adding a small amount of organic nickel salt.
  • M. Nishida, Y. Uraki and Y. Sano: Lignin gel with unique swelling property. Bioresource Tech., 88, 81 – 83 (2003).*
    2003  [Not refereed][Not invited]
  • M. Mustafaev, Z. Mustafaeva, E. Ergen, Y. Uraki, Y. Sano: Novel betulin-containing polyelectrolyte conjugates. Journal of Bioactive and Compatible Polymers, 17(4), 251-269 (2002).*
    2002  [Not refereed][Not invited]
  • Y. Miharu, Y. Uraki, K. Itoyama, F. Miyazawa, Hi. Tanibe and Y. Sano: Improvement of moisture sorption of polyurethane fiber by blending cellulose. Sen-i Gakkaishi, 58, 375-380 (2002).*
    2002  [Not refereed][Not invited]
  • Y Uraki, S Kubo, Y Sano  JOURNAL OF WOOD SCIENCE  48-  (6)  521  -526  2002  [Not refereed][Not invited]
     
    To expand the utilization of waste newspapers and lignin, activated carbon (AC) sheets, as an example of AC moldings, were prepared from those mixtures. The isolated lignins used were softwood and hardwood acetic acid lignins (SAL and HAL), softwood kraft lignin (KL), and wheat-straw lignin (WSL). The mixtures were molded into precursory sheets by thermal compression and then converted to AC sheets by carbonization and steam activation. The flexural strength of the precursory sheets was dramatically improved by additing the lignins compared to that of sheets without lignin. The strength of several sheets was more than 25MPa. This suggested that lignins act as adhesives. SAL and HAL sheets with 40% newspaper were strengthened by the carbonization, whereas the strength of other lignin sheets was depressed. Finally, the AL-based AC sheets showed higher flexural strength (>6MPa) than others. Most of the AC sheets had adsorption ability comparable to that of commercially available AC powder and granules. The capacities were almost independent of paper content. Among the AC moldings tested, the AL-based AC sheets showed the fastest adsorption to p-chlorophenol. Thus, viable AC moldings can be prepared from lignin-wastepaper mixtures, particularly SAL and HAL.
  • Y Uraki, M Morito, T Kishimoto, Y Sano  HOLZFORSCHUNG  56-  (4)  341  -347  2002  [Not refereed][Not invited]
     
    The water-soluble fraction (WS) from waste liquor of atmospheric acetic acid pulping was analyzed in order to explore its potential utilization as a carbon source for bacterial cellulose (BC) production. The unpurified WS that contained colored compounds had appreciable antibacterial activity and was therefore not used as a carbon source for BC production with the bacteria Acetobacter xylinum ATCC 10245 and 53582. However, the bacteria produced BC from purified WS of both fir and birch after activated carbon treatment, The yields of BC were much lower compared to those using glucose as a typical carbon source in the Hestrin-Schramm (HS) medium. In order to improve the cellulose production, monosaccharides derived from hemicellulose sugars in WS were modified. The WS from softwood was reduced by catalytic reduction, i.e. mannose, the major component of softwood monosaccharides derived from hemicelluloses, was converted to mannitol. In the case of hardwood WS, xylose was isomerized with glucose isomerase to xylulose. The yield of BC was considerably enhanced by both modifications of the WS. The yield of BC using the modified WS from the pulping of fir was superior to that using glucose as carbon source.
  • S. Kubo, Y. Uraki and Y. Sano: "Catalytic graphitization of hardwood acetic acid lignin with nickel (II) acetate.", Proceedings of11th Internatiuonal Symposium on Wood and Pulping Chemistry, vol. 2, 115-118 (2001).
    2001  [Not refereed][Not invited]
  • Y Uraki, A Nakatani, S Kubo, Y Sano  JOURNAL OF WOOD SCIENCE  47-  (6)  465  -469  2001  [Not refereed][Not invited]
     
    Softwood acetic acid lignin (SAL) free from a high-molecular-mass fraction could be spun at 220degreesC by a spinning machine equipped with an extruder. Although the resulting fibers required thermostabilization, this step could be conducted with a faster heating rate than that for fibers obtained from hardwood acetic acid lignin (HAL). The thermostabilized SAL fibers were converted to activated carbon fibers (ACF) by carbonization in a stream of nitrogen at 1000degreesC, followed by steam activation at 900degreesC. At an activation time of 40 min, the SAL-ACF had a larger specific surface area than the corresponding HAL-ACF. When the activation time for SAL carbon fibers was prolonged to 80 min, the adsorption capacities of resulting ACF against iodine and methylene blue were markedly increased, as was the surface area of the ACE It was found that SAL-ACF had adsorption properties comparable to those of high-performance commercial ACE Also, it had a tensile strength equal to that of a pitch-derived ACF.
  • Y. Uraki, M. Morito, T. Kishimoto and Y. Sano: "Conversion of hemicellulose sugar to carbon resources for bacterial cellulose production.", Proceedings of 11th Internatiuonal Symposium on Wood and Pulping Chemistry, vol. 2, 111-114 (2001).
    2001  [Not refereed][Not invited]
  • Y Uraki, N Ishikawa, M Nishida, Y Sano  JOURNAL OF WOOD SCIENCE  47-  (4)  301  -307  2001  [Not refereed][Not invited]
     
    A polymeric amphiphile. PE-AL, was prepared from acetic acid lignin (AL) obtained by acetic acid pulping of birch under atmospheric pressure with polyethylene glycol diglycidyl ether (PE) as the crosslinker. The behavior of PE-AL solutions and the complex formation of PE-AL with protein were investigated to clarify the function of this novel lignin derivative. The reduced viscosity of the amphiphile in aqueous solution was low (<0.3 dl/g), and it decreased with increasing concentration in dilute solution. This suggested that the PE-AL in aqueous solution has a structure similar to that of Einstein's sphere and shrinks upon hydrophobic interaction among the structural moieties in AL and the exclusive volume effect. The amphiphilic PE-AL obviously formed a complex with bovine serum albumin (BSA) at 4<degrees>C with a reaction time of about 1 week. After complex formation with cellulase for 1 week, the cellulase activity of the resulting complex is significantly enhanced and is preserved after recycling the complex for hydrolysis of cellulosic materials several times.
  • M. Nishida, Y. Uraki and Y. Sano: "Preparation of lignin based hydrogel and its interaction with amphiphilic compounds.", Proceedings of11th Internatiuonal Symposium on Wood and Pulping Chemistry, vol. 2, 43-46 (2001).
    2001  [Not refereed][Not invited]
  • S Shimamoto, Y Uraki, Y Sano  CELLULOSE  7-  (4)  347  -358  2000/12  [Not refereed][Not invited]
     
    The structure and properties of a chiral nematic phase, which reflects one hand of circularly polarized light in a narrow region of wavelength, of fully acetylated (ethyl) cellulose [(acetyl) (ethyl) cellulose, AEC] in acrylic acid (AA) were studied in comparison with (ethyl) cellulose (EC). AEC mesophase formed right-handed chiral nematic structure while EC formed left-handed one. AEC mesophase showed higher birefringence and reflection intensity. The relationship between the reflection wavelength and the polymer concentration was negatively correlated for both AEC and EC mesophases. The relationship between the reflection wavelength and the molecular weight was also negative for AEC mesophase whereas positive for EC mesophase. AEC mesophase was solidified by photopolymerization of AA moiety. It was revealed that the optical properties of AEC mesophase could be preserved by photopolymerization, since the resulting solid material reflects selectively one hand of circularly polarized light.
  • Y Uraki, R Taniwatashi, S Kubo, Y Sano  JOURNAL OF WOOD SCIENCE  46-  (1)  52  -58  2000  [Not refereed][Not invited]
     
    As an example of activated carbon (AC) moldings, AC sheets were prepared from thermoplastic acetic acid lignin by lamination. The resulting AC sheets are a new type of product that can be applied as water and air cleaners. Powdered softwood acetic acid lignin (SAL) was molded into sheets by a thermal pressing method. When the sheet was carbonized under a stream of nitrogen at 1000 degrees C, it was deformed with expansion and contained much foam. The deformation during carbonization was suppressed by the addition of pulp to the lignin. A sheet prepared by mixing lignin with pulp was directly carbonized without thermostabilization. The carbonized sheet was activated with steam for 2 h. The resulting AC sheet had adsorption properties, such as specific surface and iodine adsorption capacity, comparable to those of commercial AC powders or granules. Furthermore; the AC sheet had a larger capacity to adsorb methane than did the commercial AC powder. Therefore, SAL seems to be a promising source for the AC moldings.
  • Y Uraki, A Hanzaki, K Hashida, Y Sano  HOLZFORSCHUNG  54-  (5)  535  -540  2000  [Not refereed][Not invited]
     
    Acetic acid pulps (AAPs) have been converted to amphiphiles by hydroxypropylation. The resulting hydroxypropyl derivatives (HP-AAPs) formed self-aggregates in water. The interaction of HP-AAP molecules was investigated by a viscometric method. The reduced viscosity (eta(sp)/c) of HPA-AP in both water and chloroform was increased remarkably above a concentration of 0.1% This implies that HP-AAP molecules strongly interact with each other, caused by the hydrophobic interaction of residual lignins in water and by hydrogen bonding of polysaccharides in chloroform. The self-aggregates adsorb water-soluble fluorescent agents. The highest adsorption capacity was observed at the lowest pH among three pH conditions investigated. They also solubilized sparingly water-soluble fluorescent agents in water in larger amounts than did sodium dodecyl sulfate when used as a surfactant. These results suggest that the self-aggregates of HP-AAP adsorb low molecular mass compounds as inclusion compounds. To clarify the interaction of HP-AAP with biopolymers as high molecular mass compounds, the change in the activity of papain, a protease, in phosphate buffer (pH 6.2) was examined in the presence and absence of HP-AAP. HP-AAP acted as an inhibitor of papain at the initial stage of mixing. After mixing for 24 hours, however, the papain activity was revived and preserved for 6 days. In contrast, the papain activity vanished in the absence of HP-AAP after 24 hours because of autolysis. Therefore, HP-AAP protects papain against autolysis, resulting from tight complexation with the biopolymer.
  • Kajimoto Junko, Sano Yoshihiro, Widodo Wahyu Eko, Kishimoto Takao, Uraki Yasumitsu  Journal of the Japanese Technical Association of the Pulp and Paper Industry  54-  (9)  1252  -1259  2000  [Not refereed][Not invited]
     
    In order to develop a new pulping process with non-pollution and saving energy, softwood was subjected to pulping with 60-90% HBSs, such as 1, 4-butanediol, 1, 3-butanediol and tetrahydrofurfuryl alcohol, containing 0-10% AcOH at 200-220°C. Todomatsu (A. Sachalinensis Mast.). ezomatsu (P. Glehnii Mast.), karamatsu (L. leptolepis Gordon) and sugi (Cryptomeria japonica D. Don) were easily pulped with aqueous HBS of 70% such as butanediol-1, 4 containing 5% AcOH at 220°C for 1-2h. AcOH promoted the delignification reaction. HBS such as tetrahydrofurfuryl alcohol. butanediol-1, 3 and proplylene glycol were used with satisfactory results for HBS pulping. RHBS, which was obtained by separation of water insolubles such as HBS lignin and evaporation of water from waste liquor, was able to be reused at least five times as a HBS pulping solvent. The higher yield of HBS lignin than the amount of wood lignin is indicates that modified sugar compounds are recovered with the lignin as water insolubles. Pulp showed the strength properties equivalent to those of kraft pulp except tear index.
  • Y. Uraki, Y. Miharu, R. Funada, Y. Sano, M. Mitsuhashi, K. Itoyama and H. Tanibe: "Preparation and Characterization of Alginate-blended Rayon"., Sen-i Gakkaishi, 56, 482-486(2000).＊
    2000  [Not refereed][Not invited]
  • 『ウッドケミカルスの最新技術』<飯塚尭介, 監修>
    シーエムシー  2000  [Not refereed][Not invited]
  • Y Uraki, Y Sano  HOLZFORSCHUNG  53-  (4)  411  -415  1999  [Not refereed][Not invited]
     
    Polyhydric alcohol pulping was developed to separate components of low-quality softwoods that are produced by thinning and improvement cutting as well as to establish a self-supporting pulping system. Propylene glycol (PG) was superior to ethylene glycol (EG) as solvent for polyhydric alcohol pulping at atmospheric pressure. PG pulping of fir, larch and cedar, with sulfuric acid as a catalyst, gave satisfactory pulps with few rejects and a very low level of residual lignin as compared with EG pulping. The PG pulps were readily bleached to approximately Kappa number 1 and 80% brightness by one treatment with sodium chlorite. The yield of bleached pulp from fir was 44.7% based on chips. The bleached pulps had very high ex-cellulose content and crystallinity, and their mechanical properties were similar to those of kraft pulp. Therefore, polyhydric alcohol pulping appears to be promising for pulping of softwoods by an organosolv method.
  • Y. Urakj, N. Ishikawa, M. Nishida and Y. Sano: "Stabilization of cellulase with amphiphilic acetic acid lignin derivative", Proceedings of 10th Internatiuonal Symposium on Wood and Pulping Chemistry, vol. I, 470-473 (1999).
    1999  [Not refereed][Not invited]
  • S. Kubo, Y. Uraki Y. Sano and K.-l. Chen: ”Preparation of functional carbonaceous materials from isolated lignins”, Proceedings of10th Internatiuonal Symposium on Wood and Pulping Chemistry, vol. III, 388-393 (1999).
    1999  [Not refereed][Not invited]
  • URAKI Y., SANO Y., ITOYAMA K., TANIBE H.  キチン・キトサン研究 = Chitin and chitosan research  4-  (2)  150  -151  1998/05/15
  • S Kubo, Y Uraki, Y Sano  CARBON  36-  (7-8)  1119  -1124  1998  [Not refereed][Not invited]
     
    Infusible softwood acetic acid lignin (SAL) was converted to a Fusible one as a raw material for carbon fibers by removing the infusible high molecular mass fraction-The resulting low molecular mass fraction (SAL-L) was spun by fusion spinning after thermal treatment to remove volatile materials. Carbon fibers (CFs) were prepared From these fibers by direct carbonization without thermostabilization, leading to reduction of the production costs. The tensile strength of SAL-L CFs increased with decreasing diameter, and those of the fine SAL-L CFs were comparable to those of other lignin based CFs such as phenolated exploded lignin. Therefore, SAL-L CFs were classified into general performance grade. (C) 1998 Elsevier Science Ltd. All rights reserved.
  • Pan Xue-Jun, Sano Yoshihiro, Nakashima Hiroshi, Uraki Yasumitsu  Journal of the Japanese Technical Association of the Pulp and Paper Industry  52-  (3)  408  -415  1998  [Not refereed][Not invited]
     
    In order to make use of rice straw (Oryza sativa L. cv. Kirara 397) as agricultural wastes effectively and to develop a novel pulping method for rice straw without environmental impact, an atmospheric acetic acid pulping was studied. The results indicated that the acetic acid pulping process is a promising method for rice straw. The straw gave screened pulps with satisfactory strength properties when refluxed in 80-90% aqueous AcOH with 0.32% H2SO4 or 0.10% HCl as catalyst for 3 hours. The aqueous AcOH was recovered from the waste liquor and AcOH washings by distillation without troublesome problems, and AcOH lignin and water solubles as sugars were prepared as by-products from the concentrated waste liquor by fractional precipitation with water. The ash contents in screened pulp, fines, water solubles and AcOH lignin were about 18, 24, 18 and 1.5%, respectively. The ash in the pulp and fines consisted mainly of silica which located not in fiber and parenchyma cells but only in epidermal cells as shown by a SEM-EDXA photograph. The silica left in the pulp may function as a filler of paper.
  • Y.-G. Kim, N. Watanabe, Y. Sano, Y. Uraki and Y. Sano:"Extractives of Kitakobushi Magnolia Kobus DC. var. borealis Sarg. III. -Antibacterial and Antifungal Activity of Extractives.-", Research Bulletin of The Hokkaido University Forests, 55, 63-73 (・・・
    1998  [Not refereed][Not invited]
     
    Y.-G. Kim, N. Watanabe, Y. Sano, Y. Uraki and Y. Sano:"Extractives of Kitakobushi Magnolia Kobus DC. var. borealis Sarg. III. -Antibacterial and Antifungal Activity of Extractives.-", Research Bulletin of The Hokkaido University Forests, 55, 63-73 (1998)*
  • Y Uraki, K Hashida, Y Sano  HOLZFORSCHUNG  51-  (1)  91  -97  1997  [Not refereed][Not invited]
     
    Acetic acid pulp (AAP) containing more than 8 % residual lignin was chemically modified to prepare hydroxypropylated pulps (HP-AAPs) by treatment with propylene oxide under alkaline conditions. HP-AAPs with residual lignin had an amphiphilic properly. After negative staining, transmission electron micrographs indicated that HP-AAP formed self-aggregates in water which were converted into small particles with diameters in the nano meter range by ultrasound sonication. The aggregates were revealed to have strong hydrophobic domains by the fluorometric study of their complexes with fluorescent reagents as indicators for hydrophobicity. However, commercial hydroxypropylated cellulose and carboxymethylated AAP did not form self-aggregates and had little hydrophobic domain. These results suggest that HP-AAP aggregates in water by the hydrophobic interaction of the residual lignin, and the aggregates have a tendency to form complexes with hydrophobic materials. Thus, the amphiphilic derivatives have the same properties as inclusion compounds do.
  • S Kubo, N Ishikawa, Y Uraki, Y Sano  MOKUZAI GAKKAISHI  43-  (8)  655  -662  1997  [Not refereed][Not invited]
     
    Softwood acetic acid lignin (S-AL), obtained by aqueous acetic acid pulping of todomatsu (Abies sachalinensis Masters), is infusible. In this study, a method for conversion of S-AL to a fusible material for the preparation of lignin fibers was developed based on examination of the relationship between the thermal properties and the chemical structure of S-AL. S-AL was found to be converted to fusible material by removal of the high-molecular-mass fraction by solvent extraction with 70% acetic acid, with a yield of 80%. From a comparison of the chemical structure of the fusible and infusible fractions, we found that the structures of aromatic nuclei in the acetic acid lignin (AL), such as condensed and aryl-ether structures, were related closely to the thermal mobility of AL. The large contents of condensed and aryl-ether structures in AL seemed likely to hinder thermal motion. Therefore, the cutting of aryl-ether bonds by re-cooking with aqueous acetic acid resulted in a fusible lignin, with a yield of approximately 90%. The fusible fraction of S-AL and the re-cooked S-AL were capable of being spun by fusion spinning.
  • Uraki, Y., Chen, C. -L. and Gratzl, J. : "Sonolysis of Chloro-Organics in Bleach Plant E-1 Effluents", Holzforschung, 51 : 452-458 (1997)＊
    1997  [Not refereed][Not invited]
  • Uraki, Y., Kubo, S. and Sano, Y. : "Characteristics of Activated Carbon Fibers Prepared from Acetic Acid Lignin", Proceedings ATC '97 The 4th Asian Textile Conference, 1 : 36-41 (1997)
    1997  [Not refereed][Not invited]
  • Uraki, Y., Kubo, S., Kurakami, T., and Sano, Y. : "Activated Carbon Fibers from Acetic Acid Lignin", Holzforschung, 51(2) : 188-192 (1997)＊
    1997  [Not refereed][Not invited]
  • S. Kudo, Y. Uraki and Y. Sano : "Thermomechanical Analysis of Isolated Lignins", Holzforschung, 50 : 144-150 (1996)＊
    1996  [Not refereed][Not invited]

Books etc

  • 浦木康光 (Joint work木材成分セルロースとリグニンのエレクトロスピニング)
    シーエムシー出版 2021/03 (ISBN: 9784781315928) 9,341p
  • 表面技術
    浦木康光 (Joint work蓄電デバイス用セパレータ)
    2020/06
  • 浦木康光 (Joint workリグニンの単離・改質とリグニンを活用した機能性材料の開発)
    シーエムシー出版 2020/03 (ISBN: 9784781314945) iv, 227p
  • 加工技術
    浦木康光 (Joint workリグニンを主原料とするポリエステルフィルムの調製とその利用)
    2018/05
  • 木質の化学
    文永堂出版 2010
  • 「機能性リグニン－多糖複合体の開発」
    シーエムシー出版 2007
  • Development of functional lignin-carbohydrate complex
    CMC Publisher 2007

Association Memberships

  • リグニン学会   木質炭化学会   日本農芸化学会   アメリカ化学会   繊維学会   キチン・キトサン学会   日本木材学会   セルロース学会   高分子学会   The Wood Carbonization Research Society   American Chemical Society   The Society of Fiber Science and Technology, Japan   Japanese Society for Chitin and Chitosan   The Japan Wood Research Society   The Cellulose Society of Japan   The Society of Polymer Science, Japan   

Research Projects

  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2021/04 -2026/03 
    Author : 浦木 康光, 堤 祐司, 玉井 裕, 綿岡 勲, 鈴木 栞, 重冨 顕吾
     
    当該年度は、3つの課題について検討を行い、以下の成果を得た。 1. rCWPO-Cの高純度化と多量発現：組換体大腸菌によるタンパク質の発現と精製工程にいて、TAPS化とリフォールディングの間に遠心分離を2回の行う操作を加えた。この結果、精製rCWPO-Cの収率を維持したまま、ペルオキシダーゼの精製度を示すRZ値が約1.5倍に増加し、比活性も約1.5倍の560μmol/min/mgまで向上した。 2.細胞壁構成多糖類間および多糖類-ペルオキシダーゼ間のの相互作用解析：木材のヘミセルロース（キシラン、グルコマンナン、キシログルカン）とセルロースとの相互作用を、平衡吸着実験と速度論的解析が可能なQCM-Dを用いて行った。両測定とも、キシログルカンがセルロースに最も吸着することが明らかとなった。また、Horseradish peroxidase(HRP)と多糖類との相互作用解析では、HRPはセルロースに対し、高い親和性を示すことも分かった。さらに、多糖類が脱水素重合体(DHP)の形成に及ぼす影響も調べ、キシログルカンがDHPを多量生成させ、加えて、5-5’縮合結合の形成も促進することが示された。この結果より、一次細胞壁が縮合構造に富む理由が解明できた。 3.高分子リグニンの蛍光共鳴エネルギー移動（FRET)の測定：FRET測定の最初の取り組みとして、固体試料を対象とした蛍光顕微鏡でFRETが示されているリグニンと蛍光試薬ローダミンとの相互作用を、溶液中で検出することから検討した。使用したリグニンは広葉樹のクラフトリグニンである。この測定の結果、プロピレングリコールを溶媒とする溶液中で、FRETを観測することができた。モノリグノールとクラフトリグニンとのFRETの検出を試みたが、どちらも蛍光強度が弱かったために、明確なFRET検出には至っていない。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2018/04 -2021/03 
    Author : Uraki Yasumitsu
     
    This study clearly demonstrated the effect of hemicelluloses on ligninfication through lignin formation in the artificial polysaccharide matrices; xylan contributed to lignin formation and generation of 8-O-4' interunitary linkage, which was a major linkage in native lignin, while glucomannan inhibited lignin formation. In addition, xyloglucan, which located only at primary wall of tree, was found to enhance the frequency of 5-5' interunitary linkage. From the analysis of solution structure for isolated lignins by using size-exclusion chromatograph equipped with multi-angle laser light scattering detector, 5-5' linkage was found to be closely related to the densed structure, especially much compact structure of lignin fraction with larger molar mass compared to that with small molar mass.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2014/06 -2018/03 
    Author : Uraki Yasumitsu
     
    An aim of this study is to elucidate lignin formation mechanism (lignification), especially influence of hemicelloses, with polysaccharide matrix mimicking wood cell wall structure. Polysaccharide matrix was successfully prepared by the deposition of hemicelluloses, xylan and glucomannan, onto bacterial cellulose. Dehydrogenative polymerization of coniferyl alcohol, which was one of monolignols, was attempted in the presence of such polysaccharide matrix. As a result, the polymerization was accelerated by xylan deposition, but was inhibited by glucomannan. In addition, the structure of the resultant polymerized product (Dehydronation Polymer: DHP) was investigated on a size-exclusion chromatography equipped with a laser light-scattering detector by the comparison with solution structure of a non-branched lignin model compound that is comprised of only 8-O-4’ linkage. This investigation revealed that DHP had a significant frequency of branched structure.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2009 -2011 
    Author : URAKI Yasumitsu, TAMAI Yutaka, KODA Keiichi, HIRAI Takuro, SUGIYAMA Junji
     
    In this study, hemicellulose-adsorbed honeycomb-patterned cellulose films termed as artificail wood cell wall were developed to investigate the function of hemicelluloses in wood cell wall and to develop the cell culture for liver cells. Tensile strength and its modulus of the cellulosic films were enhanced by the adsorption of hemicelluloses, xylan and arabinogalactan (AG). Xylan adsorption and its tensile modulus were improved by microwave irradiation. We judged proposed theory for the elucidation of deformation mechanism of wood cross-scetion upon the mechanical stress from the tensile properties of honeycomb-patterned films. As a result, the theory of bending-stretching model was suitable for the elucidation, and xylan-adsorbed film showed more fitting to the theory. In addition, we evaluated AG-adsorbed honeycomb-patterned film as a culture substrate for mouse liver cells. The films with small pores were found to be a new type candidate substrate for the culture. On the other hand, the films with larger pores would be suggested to be a plate for cell array, but the number of attached cell was so small. For the industrial application, this problem should be overcome.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2007 -2010 
    Author : INOUE Takashi, HIRANO Takashi, HATANO Ryusuke, TANI Hiroshi, SAITOU Hideyuki, TAMAI Yutaka, OSAKI Mitsuru, HATA Hiroshi, HASHIDOKO Yasuyuki, URAKI Yasumitsu, TAWARAYA Keitaro, HARAGUCHI Akira, ABE Ryuichiro
     
    Tropical peat land is a huge carbon sink involving an ecosystem that is very fragile but rich in biodiversity. This study deployed on establishment of measures for optimum land use and land management based on the viewpoint of control of carbon flow in tropical peatland. Prevention of peat fire, restoration of devastated land, sustainable bioproduction, and the reduction of environment load are the special interest that is rendered for the approach.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2006 -2008 
    Author : URAKI Yasumitsu, HIRAI Takuro, TAMAI Yutaka, KISHIMOTO Takao, SUGIYAMA Junji
     
    樹木細胞壁の二次壁の特徴は、他の壁組織に比べ多量に存在するリグニンとその化学構造である。本研究では、二次壁模倣材料の創出を目的に、二次壁リグニン模倣高分子を創製して、その物性を明らかにした。さらに、ハニカムパターン化セルロースにリグニンを吸着させて二次壁模倣セルロース材料を創製して、その物性解析からリグニンが高湿度における細胞壁の強度低下を抑制することを見出すと共に、木材成分のみで高強度材料を創出できることを明らかにした。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 2003 -2005 
    Author : URAKI Yasumitsu, TAKABE Keiji, FUKUSHIMA Kazuhiko, KONDO Tetsuo, FUNADA Ryo, TAMAI Yutaka
     
    An aim of this research is to clarify the construction mechanism of tree cell wall that had the hierarchical structure from molecular level to tissue level. In addition, our objective is to create an artificial cell wall by mimicking the formation process of natural wood cell wall on the basis of the results of former subjects. In this research project, we obtained experimental results and conclusions for five subjects. Conclusion 1.Xylan is a key hemicellulose for lignification. Conclusion 2.This finding for ConClusion 1 was supported by physicochemical analysis of the interaction between hemicelluloses and lignification-related compounds. These analyses were carried out on an apparatus based on the surface plasmon resonance. Conclusion 3.We clarified solution behavior of LCC in water, such as interaction of solvent, self-assembly of LCC molecules and formation of hydrophobic domain in the self-aggregates. We proposed LCC functions in the wood from these results. Conclusion 4.we developed a new analysis method, Time of Flight・Secondary Ion Mass spectroscopy (ToF-SIMS), for lignin structure, and artificial lignin polymer, which was merely comprised of β-O-4, as a lignin model for NMR assignment. Conclusion 4 We elucidate the cell wall formation at the cell level in relation to cell-supported proteins, microtubles and actin in addition to tissue formation. Conclusion 5.we developed a methodology to create artificial cell wall on the basis of findings obtained in this study. The artificial cell wall backbone was fabricated by the conversion of bacterial cellulose to honeycomb-patterned material. The conversion was carried out by the control of the movement of cellulose-producing bacteria.
  • 人工細胞壁の創製
    科学研究費補助金
    Date (from‐to) : 2002
  • Creation of artificial cell wall
    Grant-in-Aid for Scientific Research
    Date (from‐to) : 2002
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1999 -2001 
    Author : SANO Yoshihiro, TABARA Masayoshi, URAKI Yasumitu, SHINOHARA Kunio, KISHIMOTO Takao
     
    There are a large quantity of birch tree fast-growing in a cold district, and also poor-grade biomass materials such as thinning and agricultural wastes in Hokkaido, but they have been utilized less effective use or discarded. We carried out a fundamental investigation to establish a novel biomass-conversion mill in Hokkaido to convert their biomass materials to green chemicals, fine chemicals, biodegradation plastics, bioenergy and so forth. We established two biomass refinery processes with non-pollution and save-energy. One is an atmospheric acetic acid method and another HBS method. Birch wood and other biomas materials were easily fractionated into cellulose, lignin and/or hemicellulose in almost quantitative yields. The resulting cellulose had excellent properties for paper and dissolving pulps, and biochemicals. Hemicellulose obtained as monosaccharides from the former can be used for biochemicals and food additives. Lignin can be utilized for biofuel with clean and high calorific value, and functional biopolymers (epoxide, phenol-resorcinol and maybe polyurethane resins), molding active carbons and so forth. Betulin was extracted with acetic acid and other solvents in a yield of 30% from outer bark of birch. Betulin appears to be used as raw materials for fine chemicals, biodegradation polymers, and medicine such as anti-HIZ agents.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1998 -2000 
    Author : SANO Yoshihiro, KISHIMOTO Takao, URAKI Yasumitsu
     
    Polyhydric alcohol (PHA) pulping was developed to separate components of low-quality softwoods that are produced by thinning and improvement cutting as well as to establish a new pulping process with solvent self-supplied from wood. Proplylene glycol (PG) was superior to ethylene glycol (EG) as solvent for PUA pulping at atmosphereic pressure. PHA pulping of fir, larch and cedar with PG containing sulfuric acid as a catalyst gave satisfactory pulps with few rejects and a very low level of residual lignin as compared with that with EG.PG pulps were readily bleached to approximately Kappa number 1 and 80% brightness by one treatment with sodium chlorite. The bleached pulp of fir was obtained in a yield of 44.7% of chips, had very high α-cellulose content and crystallinity, and had thesimilar strength properties to those for kraft pulp. Therefore, PHA pulping apperas to be promising for pulping of softwood, hardwood and nonwood. Lignins were isolated and freezing-dried from spent liquors in PHA pulping of fir and birch. Both the lignins were obtained in almost quantitative yields, dissolved with conventional aqueous lignin-solvents such as acetone, dioxane and pyridine, and further hot-melted. Each content of carbon was higher than those for corresponding acetic acid lignin and protolignin. Lignins of birch and fir chips had lower weight average-molecular weight of 670-710 and 720-830 than those for corresponding actic acid lignins and MWLs.
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 1998 -1999 
    Author : 浦木 康光
     
    リグニンを含むパルプをリグノセルロースと見なし、ヒドロキシプロピル化により、水及び有機溶媒に可溶な両親媒性誘導体を調製した。本年度は、両親媒性誘導体と生体高分子との相互作用による生体高分子の構造変化について検討した。さらに、相互作用を解明する基礎研究として、この誘導体の水溶液中の構造及び温度変化による形態変化についても検討を加え、この誘導体の基本的物性と利用法について考察した。 牛血清アルブミン(BSA)を生体高分子として用い、誘導体との相互作用による形態変化を円二色性スペクトルにより調べた。BSAはリン酸緩衝液中で48時間2次構造変化は起こさなかったが、96時間以降α-helix構造に由来するコットン効果が減少して変性することが示された。一方、誘導体が存在してもBSAのスペクトルは変化せず、122時間後でも構造が保たれていることが分かった。このことは、誘導体が生体高分子を取り込むような相互作用をしていることを示唆しているが、その作用は生体高分子の構造を変化させるほど強くなく、単に運動性を抑制して変性を妨げていることを意味していると思われる。 物質の取り込み現象を明らかにするために、先ず、誘導体の溶液構造を検討した。X線小角散乱から、この誘導体分子はかなり剛直な棒状高分子であることが示された。光散乱より、誘導体の会合物は球状の構造をしており、これらの結果、残存リグニンが棒状高分子を結びつけ巨大な球状構造を形成していることが明らかになった。また、誘導体は残存リグニン量が多くなると下限共溶臨界温度が低下して、体温付近で沈殿現象を生じることが示され、球状構造の空隙に取り込んだ物質を温度上昇で放出する温度感応性物質として利用できることが分かった。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1994 -1996 
    Author : SANO Yoshihiro, TAKAI Mitsuo, OZAWA Shuji, URAKI Yasumitsu
     
    Poor-grade woods obtained from thinning, storm-fallen-down and short-rotation trees were subjected to pulpings by continuous extraction systmes with organic solvents in order to utilize valuable products. The woods from most of hardwood such as birch, poplar and beech, and from spruce and todomatsu (Abies sachalinensis Masters.) as softwood were possible to be separated into AcOH pulp, hemicellulose and lignin quantitatively by a solvent pulping system with aqueous acetic acid containing a small amount of sulfuric acid or hydrochloric acid at reflux temperatures. However, thinning woods from larch and sugi (Cryptomeria japonica D.Don) yielded PHA pulps with large amounts of residual lignin by this pulping process. The larch and sugi woods were possible to be pulped by a novel polyhydric alcohol process either with sulfuric acid at reflux temperature or with acetic acid at higher temperatures. Acetic acid and polyhydric alcohols for pulping solvents may be prepared from wood polysaccharides. AcOH pulps had satsfactory properties for paper-making. The water solubles recovered as sugars from the waste liquor consisted mainly of monosaccharides such as xylose, mannose and so forth. The sugars appear to be utilized as diet sweeteners, medicines and chemicals. AcOH lignin could be converted to carbon fibers and fibrous active carbon with good quality by use of simple and economical methods because it has the characteristic hot-melting. PHA pulps had the properties for paper-grade and dissolving pulps. Lignin was recovered in quantity from the waste liquor. Hemicelluolse obtained together with the pulping solvent may be used several times for pulpings without recovery and conversion.
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1994 -1995 
    Author : SANO Yoshihiro, KOJIMA Yasuo, URAKI Yasumitsu, SANO Yuzou, FUNADA Ryo, OHTANI Jun
     
    The arrangement of cortical microtubules (MTs) in differentiating tracheids of conifers was examined by confocal laser scanning microscopy after immunofluorescent staining. The arrays of MTs in the tracheids during formation of the primary wall were not well ordered and the predominant orientation changed from longitudinal to transverse. During formation of the secondary wall, the arrays of MTs were well ordered and their orientation changed progressively from a flat S-helix to a steep Z-helix and then to a flat S-helix as the differentiation of tracheids proceeded. The orientation of cellulose microfibrils (MFs) on the innermost surface of cell walls observed by FE-SEM changed in a similar manner to that of the MTs. The MFs changed their orientation, with clockwise rotation (viewed from the lumen side), from a flat S-helix to a steep Z-helix and then from a steep Z-helix to a flat S-helix during the formation of secondary wall. These results provide strong evidence for the co-alignment of MTs and MFs during the formation of the semi-helicoidal texture of the cell wall in conifer tracheids. No tracheids in which the MTs had been disassembled were observed in any radial series during the successive steps of differentiation. The orientation of MTs might change progressively without depolymerization of MTs, supporting the dynamic helical model. On the basis of our results, we propose a model for the orientation of MTs and MFs during the differentiation of tracheids.
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 1993 -1993 
    Author : 浦木 康光
     
    1.緒言 本研究の目的は、硫酸触媒による常圧酢酸パルプ化法によって得られるリグニン(AWL)から液晶を生成する物質を調整し、最終的に液晶紡糸を行うことであった。液晶物質の調整法として2法考えられ、1つはアルキル鎖の導入やメソ-ゲンとなる官能基導入などのAWLの化学修飾による改質である。もう1つは、高機能の炭素繊維を調整するためピッチ系原料で用いられている加熱によるメソフェーズいわゆる液晶の調整である。2番目の方法は、不均一構造の物質を熱分解と同時に、熱縮合を生じさせて、できるだけ均一構造の会合体を作り液晶を発現させるもので、不均一構造を有するリグニンの液晶化には、簡便で好適な方法と思われた。そこで、この研究では、加熱条件を変えての液晶生成を検討し、走査型電子顕微鏡(SEM)、偏光顕微鏡や熱分析により液晶生成を評価した。 2.実験 (1)AWLの液晶化:AWLを空気中の開放系及びミクロオートクレーブを用いた窒素雰囲気下で昇温速度3℃/minで160℃から430℃まで加熱し、所定温度を40minまたは90min維持した。熱処理AWLのキノリン不溶部を液晶画分としてろ過で回収し、エタノールで洗浄後減圧乾燥した。(2)顕微鏡観察:キノリン不溶部をSEM及び偏光顕微鏡により観察した。 3.結果 AWLを430℃で90min加熱した試料は、SEMでメソフェーズと思われる小球体の形成が観察された。さらに、偏光顕微鏡観察から超薄片部分にクロスニコル下での発光が観察され、液晶の生成を示唆する結果が得られた。また、160℃や250℃でもSEMよりピッチ系メソフェーズでも観察されるサンゴ状組織が見られたが、偏光観察からは液晶の形成は観察されなかった。高温処理試料は、示差走査熱量分析から液晶の熱相転移に起因すると考えられる吸熱ピークが観測され、リグニン液晶がサーモトロピック液晶に近い熱挙動を示すことが示唆された。現在、この液晶の構造を電子線解析により調べると共に、紡糸条件について検討している。
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1991 -1992 
    Author : TAKAI Mitsuo, SUGIYAMA Sadao, FUJIWARA Masashi, SHIMIZU Yu-ichi, URAKI Yasumitsu, TOKURA Seiichi
     
    High resolution ^<13>C NMR spectra of alpha-chitin and beta-chitin in solid state can be distinguished from each other as well as the x-ray patterns or IR spectra. alpha-Chitin from crab or shrimp shell is known to be slightly soluble in general organic solvents and to have poor reactivity due to its rigid crystalline structure. beta-Chitin, on the other hand, from squid bone of Loligo pen, easily forms slurry when it was ground with water. This is responsible for the loose crystalline structure and the high hydrophilicity of Loligo pen chitin. Therefore it is much easier to prepare the paper sheet from beta-chitin than alpha-chitin without binder. Direct sheet preparation from Loligo pen gel is economically of greater advantage than nonwoven sheet from crab shell. The hand-made chitin paper from Loligo pen shows a high bursting factor of 7.4 and breaking length of 6.9 Km, compared with those of alpha-chitin from crab shell, 1.0 and 3.0 Km. The Loligo pen paper is obviously softer than that from crab shell as to rigidity or stiffness calculated from Young modulus. Furthermore the higher permeability of moisture together with water regain, a strong affinity for blood protein such as fibrinogen, albumin or gamma-globulin, and slow biodegradation by lysozyme were observed. Thus the pen sheet seems to be more suitable for temporarily artificial skin. In this report, the direct preparation of chitin sheet from mechanically beated loligo pen chitin was investigated. A continuous paper-making machine for the chitin was designed in bench scale and constructed in our Machine Shop. Paper of 30m long and 80mm wide can be prepared by the machine at the speed of 0.5m/min.
  • 日本学術振興会：科学研究費助成事業
    Date (from‐to) : 1991 -1991 
    Author : 浦木 康光
  • Japan Society for the Promotion of Science：Grants-in-Aid for Scientific Research
    Date (from‐to) : 1989 -1991 
    Author : SANO Yoshihiro, URAKI Yasumitu, SASAYA Takashi
     
    Separation and utilization of woody biomass were investigated by aqueous acetic acid of commercial hardwood chips(oak, alder, mangrove)with a catalst of sulfuric acid. When chips were boiled in 90% aqueous acid for 45 min, the chips-were filtrated. After repeated this pretreatment, they were cooked in a new 90% aqueous acetic acid with 0.32-0.40% H_2SO_4 for 3-4 h. Alder was easily pulped, but mangrove was done with a best deal of difficulty and produced a lot of reject. When the reject was repulped under similar conditions, it gave pulps with a good yield. Yields of the combined pulps were about 50% on basis of the starting chips for all of the species. Pulping waste liquor was concentrated under reduced pressure and poured into 5 times volume of water to divide into acetic acid lignins and saccharides. When chips were pulped for 3 h and 4 h under the same conditions, saccharides were recovered in yields of 20% and 15% based on chips, respectively, as reducing sugars. The sugar composition of the saccharides suggested that most of xylose residue in them was composed mainly of monosaccharides. The aqueous solution containing the saccharides showed a dark-brown color. Decoloration of the aqueous solution was carried out effectively with active carbon and synthetic adsorbents. Decoloration by the adsorbents(XAD-2 and XAD-4)was achieved together with cation- and anionexchange resins. XAD-2 or XAD-4 is regenerated by washing with aqueous NaOH, polar-organic solvents such as methanol et al, so may be more effectively.
  • 木質バイオマスのバイオリファイナリーと分離成分の有効利用,
    科学研究費補助金
    Date (from‐to) : 1989
  • Biorefinery of woody biomass and effective utilization of refined components
    Grant-in-Aid for Scientific Research
    Date (from‐to) : 1989

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