FUSIBILITY OF ISOLATED LIGNINS
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 β-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 β-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 γ-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.
acetic acid lignin artificial lignin polymer fusibility organosolv lignin thermomechanical analysis
Yasumitsu Uraki Keiichi Koda Takao Kishimoto Satoshi Kubo
Research Faculty of Agriculture, Hokkaido University, Sapporo 060-8589, Japan Faculty of Engineering, Toyama Prefectural University, Imizu 939-0398, Japan Department of Biomass Chemistry, Forestry and Forest Products Research Institute, Tsukuba 305-8687,
国际会议
广州
英文
315-318
2010-11-08（万方平台首次上网日期，不代表论文的发表时间）