@article{oai:mie-u.repo.nii.ac.jp:00005724,
 author = {Funaoka, Masamitsu and 船岡, 正光 and Kako, Tatsunari and 加古, 辰成 and Kubomura, Makoto and 久保村, 実},
 journal = {三重大学生物資源学部紀要 = The bulletin of the Faculty of Bioresources, Mie University},
 month = {Mar},
 note = {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.},
 pages = {27--36},
 title = {Occurrence of Diphenylmethane Type Condensation in Lignin during Heating and Sulfuric Acid Treatment of Wood},
 volume = {6},
 year = {1991}
}