京都大学 · 材料科学
本研究室では、セルロースを基盤とする持続可能なバイオマテリアルの開発を柱として、ナノセルロースと高分子の界面相互作用や複合化メカニズムに注力しています。特に、セルロース誘導体の熱可塑化やガントリスコポリマー化を応用した機能性プラスチックの創出、および生分解性ポリマーの設計的制御を進めています。また、酵素分解性や熱履歴が物性に与える影響についても、分子構造と物性の相関を解明する研究が展開されています。
Figures are computed from collected data and may differ slightly.
In recent years, the research on nanocellulose composites with polymers has made significant contributions to the development of functional and sustainable materials. This review outlines the chemistry of the interaction between the nanocellulose and the polymer matrix, along with the extent of the reinforcement in their nanocomposites. In order to fabricate well-defined nanocomposites, the type of nanomaterial and the selection of the polymer matrix are always crucial from the viewpoint of poly
A combined sulfuric acid-free ethanol cooking and pulverization process was developed in order to achieve the complete saccharification of the cellulosic component of woody biomass, thereby avoiding the problems associated with the use of strong acid catalysts. Eucalyptus wood chips were used as a raw material and exposed to an ethanol/water/acetic acid mixed solvent in an autoclave. This process can cause the fibrillation of wood chips. During the process, the production of furfural due to an e
This review surveys advances in the development of various material functionalities based on thermoplastic cellulose and related structural polysaccharide derivatives. First, the dependence of thermal (phase) transition behavior on the molecular composition of simple derivatives is rationalized. Next, approaches enabling effective thermoplasticization and further incorporation of material functionalities into structural polysaccharides are discussed. These approaches include: (a) single-substitu
Abstract Graft copolymerization of ε‐caprolactone (CL) and lactic acid (LA) onto cellulose diacetate (CDA) at the residual hydroxyl positions was conducted to obtain thermoplastic CDA. The effects of the reaction temperature and time and the CL/LA molar ratio in the feed on the progress of the graft copolymerization were investigated. The molecular weight of CDA was increased by this graft copolymerization. The oxycaproyl and lactyl molar substitutions (MS CL and MS LA , respectively) in grafted
Abstract Summary: Several different series of cellulose acetate‐ graft ‐poly(hydroxyalkanoate)s (CA‐ g ‐PHAs) were synthesized over a wide range of compositions by the graft copolymerization of lactic acid, L ‐lactide, ( R , S )‐ β ‐butyrolactone, δ ‐valerolactone and ε ‐caprolactone onto the residual hydroxyl positions of CA, by virtue of a suitable catalyst, solvent and procedure for each individual case. To achieve a diversity of molecular architectures of the respective graft copolymer serie
Enzymatic hydrolysis of selected copolymers of cellulose diacetate-graft-poly(L-lactide)s (CDA-g-PLLAs) were conducted with proteinase K for film specimens, which were solely quenched from the molten state or, further, annealed at temperatures below or above their glass transition temperatures. The hydrolysis rates depended seriously on the thermal history, as well as on the graft modification. Especially, the heat treatment, followed by physical aging or crystallization of the originally amorph
Thermal transition property of cellulose diacetate-graft-poly(L-lactide) (CDA-g-PLLA) varies depending seriously on the molar substitution (MS) of lactyl unit, as represented by a drastic Tg depression with increasing MS (0<MS< or =8) and a subsequent crystallization of the PLLA side chains (MS> or =14). To make clear the thermally induced development of supramolecular structures for this series of graft copolymers, physical aging and crystallization experiments were conducted under isothermal c
The present work demonstrates the formulation of cellulose nanofiber (CNF) or magnetic cellulose nanofiber (mgCNF) dispersed chitosan-based edible nanocoating with superior mechanical, thermal, optical, and texture properties. The fabrication of mgCNF is successfully achieved through a single-step coprecipitation route, where iron particles get adsorbed onto CNF. The thermal stability of mgCNF is improved considerably, where ∼17% reduction in weight is observed, whereas CNF degrades completely u
Indigenous honey wine, known locally as ogol , was collected in a village of the Majangir ethnic group in Southwest Ethiopia, and the procedure for ogol fermentation was investigated. A fermentation yeast was first isolated from ogol and identified as being a strain of the genus Saccharomyces cerevisiae . Honey wine made with S . cerevisiae ET99 contains 16.5% (v/v) ethanol; the acidity and pH were 6.0 and 3.8, respectively. Volatile ester and higher alcohol were detected by gas chromatography.
We found that cellulosic liquid-crystalline films displayed not only a wide-ranging colour change but also inversion of circular dichroism upon a mechanical stimulus.
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