交联聚丙烯压电膜的热拉伸法制备和压电特性

Fabrication and Piezoelectricity of Cross-linked Polypropylene Films Treated by Hot-Stretching Process

通过热拉伸法制备了交联聚丙烯(XPP)压电驻极体薄膜。利用扫描电镜(SEM)技术观察了薄膜的微观结构,采用准静态法测量了该功能膜在不同拉伸比下的压电常数d33,并分析了材料结构对d33带来的影响。结果表明,样品获得压电效应的拉伸比阈值是70%,且随拉伸比的提高,样品的d33逐渐增强;当拉伸比为150%时,d33达到35 pC/N。对于所有经过热拉伸处理的样品,其d33在30 kPa的压强范围内都具有良好的线性度。样品表面结构对其压电效应亦有影响,选取粗糙面进行电晕充电更易于提高XPP膜的电极化效率,获得较高的压电系数。

Piezoelectret film made by cross-linked polypropylene foam sheet was prepared by hot-stretching process.The microstructure of stretched films was observed by SEM technique.The piezoelectric d33-coefficients of the samples,with various degrees of elongation,were determined by a quasi-static method.The applied pressure dependence of piezoelectric d33-coefficients was investigated.The influence of surface structure on piezoelectric activity was discussed also.The results show that the piezoelectricity begins at the degree of elongation 70%.The piezoelectric d33-coefficients are enhanced with the increases of elongation degree.The d33 value of 35 pC/N is obtained for the sample stretched to elongation degree of 150%.All the samples show good linearity in the range of applied pressure up to 30 kPa.Improved piezoelectric activity is obtained for the stretched XPP films when the rough surfaces were exposed to corona.