Authors: Kazuya Minato Hiroyuki Hosoo Shingo Kawaguchi
Publish Date: 2007/06/01
Volume: 53, Issue: 3, Pages: 255-257
Abstract
Participation of lignin in the reaction between vaporphase formaldehyde and wood was examined by using gradually delignified wood meal A fi rstorder rate equation was successfully applied to the weight gain data From the estimated reaction parameters such as rate constant k and ultimate weight gain a the reactivity toward formaldehyde was discussed among wood components and compared with that for acetylation k decreased monotonously with progress of the elimination of lignin suggesting that the reaction rate of lignin is dominant over that of whole wood and the decrease in the ratio of lignin retarded the reaction of wood as a whole On the other hand a increased with decreasing lignin content This may be attributable to the enhanced reactivity of the remaining lignin due to some structural changes and to the increase in the number of reactive sites in polysaccharides as a result of their exposure accompanying the elimination of lignin The dependencies of k and a on the lignin content were not similar to the case for acetylation probably because of the difference in the reaction phase In vaporphase formaldehyde treatment the remaining lignin reacts as it is whereas in liquidphase acetylation it would undergo rearrangement or swelling of the structure in the reaction solution
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