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Occurrence of Diphenylmethane Type Condensation in Lignin during Heating and Sulfuric Acid Treatment of Wood Funaoka, Masamitsu 船岡, 正光 Kako, Tatsunari 加古, 辰成 Kubomura, Makoto 久保村, 実 657 Acid hydrolysis Heating Lignin condensation Dipheylmethane Nucleus exchange reaction application/pdf The formation and quantity of diphenylmethane type structures in lignin during heating and sulfuric acid treatment of wood were investigated quantitatively by a method combining nucleus exchange and nitrobenzene oxidation. More than 60% of non-condensed units were rapidly converted to diphenylmethane type units at early stage of the treatment with concentrated sulfuric acid. After that, further condensation of lignin scarcely occurred. The formation ratio of diphenylmethane type to other type condensed units was about three during the treatment with concentrated sulfuric acid. The modification of lignin during heating of wood began above 120℃ and was mainly diphenylmethane type condensation. About 40 and 75% of non-condensed units were convered to diphenylmethane type units by heating dry and wet wood meals at 220℃, respectively. The conversion rate to diphenylmethane type units doubled by increasing the temperature from 180 to 220℃ and by the presence of water. Faculty of Bioresources, Mie University 1991-03-28 eng departmental bulletin paper VoR http://hdl.handle.net/10076/3323 https://mie-u.repo.nii.ac.jp/records/5724 0915-0471 AN10073846 三重大学生物資源学部紀要 = The bulletin of the Faculty of Bioresources, Mie University 6 27 36 https://mie-u.repo.nii.ac.jp/record/5724/files/AN100738460000604.pdf application/pdf 418.3 kB 2017-02-18