Dielectric properties of Simon poplar wood flour/polypropylene composite at oven-dry state

作     者：WANG Lei CAO Jin-zhen WANG Yi 

作者机构：College of Materials Science and Technology Beijing Forestry University Beijing 100083 E R. China 

出 版 物：《Forestry Studies in China》 (中国林学（英文版）)

年 卷 期：2008年第10卷第4期

页      面：265-269页

学科分类：0907[农学-林学] 08[工学] 0829[工学-林业工程] 09[农学] 

基　　金：funded by the National Natural Science Foundation of China (Grant No. 30871966) 

主　　题：Simon poplar wood flour/polypropylene composite wood content dielectric relaxation methanol group 

摘      要：Interfacial compatibility is a crucial factor to the performance of wood-plastic composites （WPCs）. Yet, so far, the coupling mechanisms of WPC have not been completely understood. In order to further clarify the interfacial coupling mechanism, the dielectric constant and dielectric loss factor of Simon poplar wood flour/polypropylene composites without additives at different wood contents were measured at oven-dry state, and parameters and thermodynamic quantities of the relaxation process were also analyzed and calculated. Consequently, an obvious relaxation process based on the reorientation of methanol groups in amorphous region of wood cell wall was observed exactly that its dielectric loss factor peak decreased with the decreasing wood content within the measured range of 50%-100%. With the trend of dielectric relaxation strength, the two changing trends both revealed that the existence of polypropylene could hinder reorientation of methanol groups. Following the decreasing wood contents, the effect of the hindrance on the dielectric properties turned obvious gradually. It elucidated that introduction of polypropylene caused the quantities of hydrogen bonds formed between each methanol group and the groups around it change. The same conclusion could be drawn from the analysis of thermodynamic quantities during the dielectric relaxation progress.