杨书宇　范勇　陈昊　杨瑞宵　郭佳

摘 要：采用微乳化-相转变法制备纳米SiO2分散液，与聚酰胺酰亚胺树脂机械共混并流延成膜，制成不同纳米含量的复合材料。采用透射电子显微镜（TEM）和傅里叶变换红外光谱（FTIR）对材料进行表征，按照IEC60343的标准测试了材料的耐电晕寿命和其它介电性能，并进行了热重分析。结果表明，纳米粒子在PAI基体中分散均匀且反应完全;加入纳米粒子提高了材料的热稳定性;随纳米粒子含量的增加，电导率、介电常数和介质损耗均发生有规律的变化，PAI复合材料的耐电晕寿命随SiO2含量的增加而增加，纳米粒子含量达到20%时，耐电晕寿命为17.35h，是纯PAI材料的8倍以上;击穿强度随纳米粒子含量的增加而减小。

关键词：聚酰胺酰亚胺;纳米SiO2;介电性能;热性能

DOI：10.15938/j.jhust.2019.03.020

中图分类号： TM215.3

文献标志码： A

文章编号： 1007-2683（2019）03-0123-07

Abstract：The nanoSiO2 dispersions were prepared by microemulsificationphase transformation method and mechanically blended with polyamideimide resin， and then cast into films with different nanocontents. Nanocomposite films were characterized by transmission electron microscopy （TEM） and Fourier transform infrared spectroscopy （FTIR）. The corona resistance life and other dielectric properties of the material were tested in accordance with the IEC60343 standard and thermogravimetric analysis was carried out. The results show that nano SiO2 particles are uniformly dispersed in PAI matrix and materials reacted completely. The thermal stability of the composites are enhanced by adding nano particles. With the increase of SiO2 content， the electrical conductivity， dielectric constant and dielectric loss changes regularly. Compared with pure PAI， the corona resistance life of nanocomposite with 20% SiO2 is 17.35h， which increases more than eight times. However， the breakdown strength of nanocomposites is a little lower with increase of nanoSiO2 loading.

Keywords：polyamideimide; nanoSiO2; dielectric properties; thermal property

0 引 言

聚酰胺酰亚胺（PAI）是一种具有良好的耐热性、介电和机械性能的高分子材料，被广泛应用于航空航天、电气电子等领域，如：漆包线漆、飞行器烧蚀材料等[1-5]。但随着现代高压电气技术的不断发展，传统的聚酰胺酰亚胺材料在持续电晕放电作用下很难长期保持绝缘性能，导致绝缘系统过早被破坏，降低了電机或电器的使用寿命。

近年来，纳米技术的发展给纳米材料科学带来了广阔的前景。由于纳米粒子具有特殊的尺寸效应，利用纳米粒子掺杂改性后的复合材料具备传统复合材料所不具备的优异性能[6-11]。纳米SiO2是纳米复合材料中最常用的增强材料之一，具有颗粒尺寸小、键能高和耐热性好等优点。……