文献类型：期刊文献

英文题名：Molecular-level characterization of changes in the mechanical properties of wood in response to thermal treatment

作者：Wang, Dong[1] Fu, Feng[2] Lin, Lanying[2]

第一作者：Wang, Dong

通信作者：Lin, LY[1]

机构：[1]Northwestern Polytech Univ Culture & Heritage, Xian, Shaanxi, Peoples R China;[2]Chinese Acad Forestry, Res Inst Wood Ind, Beijing, Peoples R China

年份：2022

卷号：29

期号：6

起止页码：3131-3142

外文期刊名：CELLULOSE

收录：;EI(收录号：20221111772997);Scopus(收录号：2-s2.0-85125906938);WOS:【SCI-EXPANDED(收录号:WOS:000766039300001)】；

基金：The authors gratefully acknowledge the financial support of the Nature Science Foundation of China (No.32101458), the Fundamental Research Funds for the Central Universities (D5000210672) and the Nature Science Foundation of China (No. 31890772).

语种：英文

外文关键词：Thermal treatment; FTIR spectroscopy; Hemicellulose; Cellulose microfibrils; Mechanical properties

摘要：Thermal treatment can improve the dimensional stability of wood, but it also decreases wood's toughness, or increases its brittleness. In this paper, combining FTIR spectroscopy and mechanical analysis were used to monitor wood molecular straining and deepen the micromechanical understanding of thermally-treated wood. The degradation of hemicellulose increased as the thermal treatment temperature increase, and the 220 degrees C treatment also led to cellulose microfibrils reorientation. The results of static tension FTIR spectra of thermally-treated wood indicated that the absorption peak of cellulose glycosidic bond underwent a substantial bandshift to lower wave numbers as the tensile strain increase, but the characteristic peak position of the lignin was no obvious change during stretching. For the 160-200 degrees C treated samples, the bandshift ratios of cellulose C-O-C glycosidic bond increased upon increasing the temperature; Furthermore, the intensities of the two split peaks of cellulose at 1169 Ycm(-1) and 1435 -cm(-1) in 0 degrees polarization dynamic FTIR spectra decreased upon increasing the treatment temperature, indicating the elasticlike response of cellulose for thermally-treated wood decrease. For the 220 degrees C treated sample, the bandshift ratio of cellulose glycosidic bond decreased compared with other thermal treatment samples, but the intensities of the two split peaks of cellulose increased again. Those results indicated that the shear slipping between cellulose microfibrils decrease and microfibrils reorientation due to hemicellulose degradation after thermal treatment may cause the toughness of the thermallytreated wood decrease, or the brittleness increase.