五层纳米SiO_2-Al_2O_3/聚酰亚胺复合薄膜的制备及性能

Preparation and properties of five layer nano SiO_2-Al_2O_3/polyimide composite film

采用浸胶法制备了一系列SiO_2-Al_2O_3/聚酰亚胺(SiO_2-Al_2O_3/PI)五层耐电晕薄膜AmAnPAnAm,其中中间层(P)为纯PI薄膜,外层(Am)、次外层(An)分别为SiO_2-Al_2O_3掺杂不同质量分数的纳米SiO_2-Al_2O_3/PI薄膜。采用TEM、FTIR、宽频介电谱仪、电导电流测试仪、耐电晕测试仪、介电强度测试仪和拉伸实验机对五层纳米复合PI耐电晕薄膜的微观结构、介电性能和力学性能进行了表征和测试。结果表明,SiO_2-Al_2O_3/PI复合薄膜掺杂层形成了分布均匀的有机/无机复合结构;SiO_2-Al_2O_3纳米粒子的保护作用是影响复合材料耐电晕性能的主要因素,复合薄膜A32A16PA16A32的耐电晕寿命最大,为23.4h;外层掺杂量对五层SiO_2-Al_2O_3/PI复合材料的介电强度影响较大,复合薄膜A20A28PA28A20的介电强度最大,为302.3kV/mm;通过对五层复合结构的设计,可以在兼顾材料力学性能的同时,提高其耐电晕寿命和介电强度。

A series of nano SiO2-Al2O3/polyimide（SiO2-Al2O3/PI）of five layer structure corona resistant film AmAnPAnAm were prepared by dipping method,the middle layer（P）was pure PI film,the outer layer（Am）and the secondary layer（An）were nano SiO2-Al2O3/PI composite film doped with different SiO2-Al2O3 mass fraction.The microstructure,dielectric properties and mechanical properties of five layer nano SiO2-Al2O3/PI composite film were characterized by TEM,FTIR,broadband dielectric spectrometer,conduction current tester,corona resistance tester,dielectric strength tester and tensile test machine.The results show that the organic/inorganic composite structure is formed in the doped layer of five layer nano SiO2-Al2O3/PI composite film.The protection of SiO2-Al2O3 nanoparticles is the main factor affecting the corona resistance of five layer nano SiO2-Al2O3/PI composite film,and the corona resistant life of five layer nano SiO2-Al2O3/PI composite film A32 A16 PA16 A32 is the most,which is 23.4 h.The amount of doping in the outer layer has a great influence on the dielectric strength of the five layer composite,the dielectric strength of the composite film A20 A28 PA28 A20 is the largest,which is 302.3 kV/mm.By designing composite structure of five layer film,the mechanical properties of the five layer nano SiO2-Al2O3/PI composite film can be improved as well as the corona resistant life and dielectric strength of the material.