文献类型：期刊文献

英文题名：Viscoelastic Properties of the Chinese Fir (Cunninghamia lanceolata) during Moisture Sorption Processes Determined by Harmonic Tests

作者：Zhan, Tianyi[1,2] Lu, Jianxiong[1] Jiang, Jiali[1] Peng, Hui[1] Li, Anxin[1] Chang, Jianmin[3]

第一作者：Zhan, Tianyi

通信作者：Jiang, JL[1]|[a0005c4a974b7fbd344a8]蒋佳荔;

机构：[1]Chinese Acad Forestry, Res Inst Wood Ind, State Key Lab Tree Genet & Breeding, Beijing 100091, Peoples R China;[2]Nanjing Forestry Univ, Coll Mat Sci & Engn, Nanjing 210037, Jiangsu, Peoples R China;[3]Beijing Forestry Univ, Coll Mat Sci & Technol, Beijing 100083, Peoples R China

年份：2016

卷号：9

期号：12

外文期刊名：MATERIALS

收录：;WOS:【SCI-EXPANDED(收录号:WOS:000390953400066)】；

基金：This work was financially supported by the National Natural Science Foundation of China (No. 31570548).

语种：英文

外文关键词：Chinese fir; sorption; viscoelasticity; harmonic test; mode of RH increment; plasticization effect; unstable state

摘要：Measured by harmonic tests, the viscoelastic properties of Chinese fir during moisture sorption processes were examined under three relative humidity (RH) modes: RHramp, RHisohume, and RHstep. The stiffness decreased and damping increased as a function of the moisture content (MC), which is presumed to be the effect of plasticization and an unstable state. The increasing damping was associated with the breaking of hydrogen bonds and the formation of free volume within polymer networks. The changes of loss modulus ratio at 1 and 20 Hz, E-1Hz ''/E-20Hz '', proved the changing trend of the unstable state. Higher ramping rates aggravated the unstable state at the RHramp period, and higher constant RH levels provided more recovery of the unstable state at the RHisohume period. Changes of viscoelastic properties were associated with RH (varied or remained constant), and the application of Boltzmann's superposition principle is a good approach to simulate viscoelasticity development.