An effective approach to enhance temperature independence of dielectric properties for polyarylene ether nitrile films
- 作者：Hailong Tang ; Xu Huang ; Xulin Yang ; Jian Yang ; Rui Zhao ; Xiaobo Liu ; liuxb@uestc.edu.cn
- 关键词：Polyarylene ether nitrile ; 4 ; 4&prime ; -bis(3 ; 4-dicyanophenoxy)biphenyl ; Crosslinking ; Temperature independence ; Thermal properties ; Dielectrics
- 刊名：Materials Letters
- 出版年：2012
- 期刊代码：59_0167577x
- 类别：ms
- 出版时间：15 May, 2012
- 卷：75
- 期：Complete
- 页码：218-220
- 文件大小：583 K
摘要
A series of crosslinked polyarylene ether nitrile films with different crosslink densities were prepared by using 4,4鈥?bis(3,4-dicyanophenoxy)biphenyl as a novel crosslinking agent. The crosslinking reaction was described as the thermally induced cyclotrimerization of the nitrile functional groups to the stable sym-triazines. After thermal crosslinking, the microstructure has been changed from a microscopic phase-separation system to a homogeneous system. The glass transition temperature and 5%weight loss temperature were increased up to 181 掳C and 484 掳C, respectively. More importantly, the temperature independence of both dielectric constant and dielectric loss was dramatically improved by the crosslinking, and the dielectric properties were found to be relatively stable with respect to temperature before the turning point temperature, which is very near to the glass transition temperature.