文献类型：期刊文献

英文题名：Effects of Time and Temperature on the Viscoelastic Properties of Chinese Fir Wood

作者：Jiang, Jiali[1] Lu, Jianxiong[1] Huang, Rongfeng[1] Li, Xiaoling[1]

第一作者：蒋佳荔

通信作者：Lu, JX[1]

机构：[1]Chinese Acad Forestry, Key Lab Wood Sci & Technol, State Forestry Adm, Res Inst Wood Ind, Beijing 100091, Peoples R China

年份：2009

卷号：27

期号：11

起止页码：1229-1234

外文期刊名：DRYING TECHNOLOGY

收录：;EI(收录号：20100412667239);Scopus(收录号：2-s2.0-74849104760);WOS:【SCI-EXPANDED(收录号:WOS:000274667700009)】；

基金：This work was funded by the National Natural Science Foundation of China (No. 30671635 and No. 30825034).

语种：英文

外文关键词：Chinese fir; Dynamic viscoelastic properties; Isothermal process; Real-time measurement

摘要：The effects of time and temperature on dynamic viscoelastic properties of Chinese fir (Cunninghamia lanceolata [Lamb.] Hook) were investigated using dynamic mechanical analysis in this study. The isothermal tests were applied to the small clear specimens with a moisture content of about 0.6% at constant temperatures ranging from 25 to 200 degrees C for 550min at atmospheric pressure. Changes in storage modulus and loss tangent with heating time were examined. The results indicated that heating time mainly resulted in thermal softening, thermal degradation of wood, and the reduction of wood stiffness. At more than 60 degrees C, the reduction in storage modulus was accelerated generally as the wood was subjected to a higher temperature or longer heating time. At constant temperatures of 140 and 160 degrees C, a relaxation phenomenon was observed with a slight change in weight, which could be attributed to the relocation of lignin molecules. At the temperature range of 140 to 180 degrees C, the higher the heating temperatures, the earlier the tan peak appeared. It is suggested that the wood thermal softening occurs at higher temperatures with shorter heating times or at lower temperatures with longer heating times. At temperatures of 180 and 200 degrees C, the loss of amorphous polysaccharides due to thermal degradation is considered to be the main factor affecting wood viscoelasticity.