聚酰亚胺基BN微纳米复合材料的电气绝缘性能研究

Study on Insulating Properties of Polyimide-based BN Micro-nano Composites

通过原位聚合法制备了不同BN掺杂含量的聚酰亚胺基微纳米复合材料,使用扫描电镜、偏光显微镜、电气强度测试仪、介损及介电常数测量系统、皮安表和耐电晕老化实验装置对不同掺杂含量的微纳米复合PI薄膜的结构和电性能及耐电晕老化性能进行了研究。结果表明:随着BN微纳米颗粒掺杂量的增加,复合PI薄膜的电气强度先增大后减小,当掺杂含量为1%时,交流电气强度达到最大值219.6 kV/mm。掺杂BN后,复合PI薄膜的介电常数和介质损耗都有所增加,在高温下的电导电流小于纯PI薄膜。随着BN掺杂量的增加,复合PI薄膜的耐电晕老化性能逐步提升,在掺杂含量为20%时,复合PI薄膜的耐电晕老化时间是纯PI薄膜的116.7倍。

Polyimide-based micro-nano composites with different BN doping contents were prepared via in-situ polymerization method, and their structure, electrical properties, and corona resistance ageing performance were studied by scanning electron microscope, polarizing microscope, electric strength tester, dielectric loss tester, picoammeters, and corona resistance ageing test device. The results show that the electric strength of the PI composite films increases at first and then decreases with the increase of BN doping content, and the AC electric strength reaches the maximum value 219.6 k V/mm when the doping content is 1%. After doping, the dielectric constant and dielectric loss of the PI composite films increase, and the electrical conductivity is less than that of pure PI film at high temperature. With the increase of BN doping content, the corona ageing resistance performance of the PI composite films increases gradually.When the doping content is 20%, the corona ageing resistance time of the PI composite film is 116.7times longer than that of pure PI film.