聚酰亚胺纳米复合薄膜耐电晕机理研究  

Research on Corona Resistance Mechanism of Polyimide Nano Composite Films

作　　者：张兴涛[1] 吴广宁[1] 杨雁[1] 钟鑫[1] 吴旭辉[1] 朱健[1] 

机构地区：[1]西南交通大学电气工程学院,成都610031

出　　处：《绝缘材料》2016年第8期17-20,25,共5页Insulating Materials

基　　金：国家自然科学基金资助项目(51177136)

摘　　要：聚酰亚胺(Polyimide,PI)因其具有良好的热稳定性和优异的耐电晕特性广泛应用于变频电机中,添加纳米粒子可以有效提高PI薄膜的绝缘性能。为了系统的研究PI纳米复合薄膜的耐电晕机理,利用原位聚合法制备了纯PI膜和纳米Al2O3掺杂的PI膜,测试两种薄膜的表面电导率、体积电导率、热失重(TGA)以及高频方波脉冲下的耐电晕时间,并用SEM观测两种薄膜击穿后的表面形貌。结果表明:添加纳米粒子使PI薄膜的电导率、热分解温度和耐电晕时间增加;电晕放电的侵蚀使得两种薄膜表面都出现微孔和沟壑,PI/Al2O3薄膜表面析出纳米粒子;在电晕侵蚀过程中,纳米PI薄膜强的表面电荷扩散能力和高的热稳定性,加上析出的纳米粒子对电子和光子的屏蔽阻挡作用,是PI薄膜耐电晕性能增强的主要原因。Polyimide （PI） has been widely used in inverter-fed motors because of its excellent thermal stability and corona resistance. It was found that the addition of nanoparticles can improve the corona resistance of PI films. In order to systematically study the corona resistance mechanism of PI nano composite films, PI film and PI/Al2O3 film were prepared through in situ polymerization method, and their surface and volume conductivity, thermal decomposition temperature, and corona resistance time under high frequency impulse voltage were tested. Moreover, the microstructure of two films after breakdown was observed by scanning electron microscope （SEM）. The results show that the conductivity, thermal decomposition temperature, and corona resistance of PI film increase after adding nanoparticles. After eroding by the corona discharge, the surface of two films shows micropores and gaps, and some nanoparticles separate out on the surface of PI/Al2O3 films. In the process of corona erosion, the strong ability of surface charge diffusion, high thermal stability, and blocking effect of the precipitated nanoparticles of PI/Al2O3 films are the main reasons of corona resistance increase for PI films.

关 键 词：聚酰亚胺 PI/Al2O3薄膜 电导率 热失重 耐电晕机理 

分 类 号：TM215.3[一般工业技术—材料科学与工程] TQ323.7[电气工程—电工理论与新技术]