文献类型：期刊文献

英文题名：Effects of thermo-hygro-mechanical (THM) treatment on the viscoelasticity of in-situ lignin

作者：Guo, Juan[2] Yin, Jiangping[2] Zhang, Yonggang[2] Salmen, Lennart[1] Yin, Yafang[2]

第一作者：郭娟

通信作者：Salmen, L[1];Yin, YF[2]

机构：[1]RISE Bioecon, Box 5604, SE-11486 Stockholm, Sweden;[2]Chinese Acad Forestry, Res Inst Wood Ind, Beijing 100091, Peoples R China

年份：2017

卷号：71

期号：6

起止页码：455-460

外文期刊名：HOLZFORSCHUNG

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000401835900001)】；

基金：The authors would gratefully like to acknowledge the financial support from the Chinese National Natural Science Foundation (No. 31370559) and State Administration of Foreign Experts Affairs P.R. China (P163036008). Dr. Toshiro Morooka from Research Institute for Sustainable Humanosphere, Kyoto University, Japan is acknowledged for the compression steam treatment of the wood samples and Mrs. Anne-Mari Olsson and Dr. Jasna S. Stevanic from Innventia AB, Sweden are acknowledged for technical support of the dynamic mechanical analysis measurement. The Wallenberg Wood Science Center is acknowledged for the support of the work at Innventia.

语种：英文

外文关键词：compression ratio; dynamic mechanical analysis; earlywood; latewood; lignin; softening; steam temperature; wood

摘要：For producing wood products without fractures based on thermo-hygro-mechanical (THM) treatments, it is essential to understand how steaming and compression change the wood softening and cell wall components. In this paper, the effects of compression combined with steam treatment (CS) on the viscoelasticity of the in-situ lignin of Chinese fir has been investigated through dynamic mechanical analysis (DMA) under fully saturated conditions. Several variations were studied, such as the softening temperature (T-g) and apparent activation energy (Delta H-a) of the softening process in response to CS treatment conditions (such as steam temperature and compression ratio) under separate consideration of earlywood (EW) and latewood (LW). No difference between EW and LW with respect to the viscoelasticity was noted. T-g and Delta H-a of the lignin softening were nearly unaffected by the compression ratio, but were highly influenced by the steam temperature. The T-g decreased significantly with CS treatments at or above 160 degrees C, but showed no appreciable change, compared to the native wood, at the lower steaming temperature of 140 degrees C. Delta H-a increased at higher steam temperatures, while Delta H-a showed a decreasing tendency with decreasing Tg. This indicates that lignin undergoes a simultaneous depolymerization as well as a condensation during CS treatment.