文献类型：期刊文献

英文题名：Frequency-dependent viscoetastic properties of Chinese fir (Cunninghamia lanceolata) under hygrothermal conditions. Part 2: moisture desorption

作者：Zhan, Tianyi[1,2] Jiang, Jiali[1] Lu, Jianxiong[1] Zhang, Yaoli[2] Chang, Jianmin[2]

第一作者：Zhan, Tianyi

通信作者：Lu, JX[1]

机构：[1]Chinese Acad Forestry, Res Inst Wood Ind, Hunan Collaborat Innovat Ctr Effect Utilizing Woo, Beijing 100091, Peoples R China;[2]Nanjing Forestry Univ, Coll Mat Sci & Engn, Nanjing 210037, Jiangsu, Peoples R China

年份：2019

卷号：73

期号：8

起止页码：737-746

外文期刊名：HOLZFORSCHUNG

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000476623800004)】；

基金：This work was financially supported by the National Natural Science Foundation of China (funder id: http://dx.doi.org/10.13039/501100001809, no. 31700487), the Natural Science Foundation of Jiangsu Province (CN) (funder id: http://dx.doi.org/10.13039/501100004608, no. BK20170926), the Innovation Fund for Young Scholars of Nanjing Forestry University (CX2017002) and the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD). Tianyi Zhan would like to gratefully acknowledge the financial support from the Jiangsu Provincial Government Scholarship Program.

语种：英文

外文关键词：frequency-dependent; hygrothermal condition; mechanosorptive effect; moisture desorption; non-equilibration status; time-moisture superposition; viscoelasticity

摘要：The frequency-dependent viscoelasticity of Chinese fir (Cunninghamia lanceolata) during moisture desorption was investigated and the applicability of the time-moisture superposition (TMS) relation on wood stiffness and damping during the moisture desorption was verified. The hygrothermal conditions for the moisture desorption were set up as six constant temperatures ranging from 30 to 80 degrees C and three relative humidity (RH) levels at 0, 30 and 60%. Due to the elimination of water during the moisture desorption, the stiffness of the Chinese fir increased, whereas the damping decreased. With the increase in frequency, increased stiffness and decreased damping were observed. Utilizing the TMS relation, it was possible to construct master curves of wood stiffness at temperatures ranging from 30 to 80 degrees C. The linear relationship between the shift factor and the moisture content (MC) manifested a low intermolecular cooperativity between the polymers and a narrow relaxation window. However, the TMS relation was not able to predict the wood damping properties during the moisture desorption, because wood is a multi-relaxation system. The non-proportional relationship between the free volume and MC during the moisture desorption may also explain why the TMS relation failed to construct master curves of the wood damping properties.