方波脉冲下聚酰亚胺/纳米复合薄膜耐电晕特性研究

本文为探究在方波脉冲下聚酰亚胺(polyimide,PI)/纳米复合薄膜的耐电晕特性,采用原位聚合法制备了纯膜和掺杂纳米氧化铝的复合薄膜,通过傅里叶红外光谱(FTIR)技术分析了薄膜的化学结构,测量了纯膜和纳米膜的表面电阻率,并在重复方波脉冲下进行耐电晕实验,最后运用扫描电子显微镜(SEM)分析电晕击穿前后薄膜的微观形态。实验结果表明:纯膜和纳米膜的耐电晕时间都会随着电压的升高而降低,并且在同一电压下,纳米膜的耐电晕特性优于纯膜。通过测试分析,从纳米粒子和聚合物基体间形成的界面、薄膜表面电荷分布、薄膜试样击穿过程3个方面对纳米薄膜优异的耐电晕特性给出了解释。

Study on Corona Resistance Characteristics of Polyimide/Nano Composite Films Under Condition of Square Impulses

In this paper,for exploring the corona resistance characteristics of polyimide/nano composite films under repetitive square impulse,pure polyimide and polyimide doped with nano alumina films are made by in-situ polymerization,and the chemical structure of the two kinds of films are analyzed by Fourier transform infrared spectroscopy (FTIR). Besides,the surface resistivity is measured. Then corona resistance test of film under repetitive square impulse is carried out and finally,the morphology before and after corona aging is analyzed through scanning electron microscope (SEM) and the mechanism of cor-ona resistance of film is investigated further. It is shown by the experimental result that the lifetime of both pure polyimide and nano composite decrease with the increase of voltage and,at the same voltage, the corona resistant characteristic of nano composite is superior to that of pure polyimide. The corona res-istant characteristic of nano composite from such three aspects as interface between nanoparticles and polymer matrix,surface charge distribution and breakdown process is explained.