聚对亚苯基二亚甲基的化学气相沉积聚合

用化学气相沉积(CVD)聚合法制备了聚对亚苯基二亚甲基(PPX)膜,由傅立叶变换红外光谱(FTIR)图证实了其化学结构.采用热重分析(TGA)研究了PPX的热降解性能,结果表明,在空气氛围中由于氧气的参与,其热稳定性比在N2中差,热氧化降解明显.PPX具有较好的耐溶剂性和抗化学氧化性能,膜的吸水速率和吸水率也比较小,常温常压下3 h后才能达到吸水平衡.PPX膜的水汽渗透率随温度和湿度的升高而升高,用Arrhenius方程拟合可计算得到水汽在膜中渗透扩散的表观活化能为12.4 kJ.mol-1.PPX膜的动态力学温度谱表现出典型的结晶聚合物的行为,晶区中的次级转变造成了PPX在玻璃化转变后,随温度提高损耗因子出现的反常升高,以及储能模量的持续、平缓下降,而不同于非晶聚合物的突然下降.

Studies on Chemical Vapor Deposition Polymerization and Propertie of Poly(p-xylylene)

In the present work poly(p-xylylene)(PPX) is prepared by chemical vapor deposition(CVD) polymerization from paracyclophane.Thermal gravimetrical analysis(TGA) is used to study the thermal degradation.It is found that the onset of thermal degradation of poly(p-xylylene) in air is much lower than that in N2 due to the existence of O2 in the air.PPX has good solvent resistance and chemical oxidation resistance.The water absorption of PPX is also low.The water vapor permeation in poly(p-xylylene) increases with the increasing of humidity and temperature.The apparent activation energy of water vapor permeation in poly(p-xylylene) is 12.4 kJ/mol,which can be calculated from the fitting results of Arrhenius equation.The dynamic mechanical properties of PPX show the typical behavior of the crystalline polymers.