潮湿环境下聚酰亚胺/Al_2O_3纳米复合薄膜表面电荷及击穿特性研究

Surface Charge and Breakdown Characteristic of Polyimide/Al_2O_3 Nanocomposite Films in Moist Environment

采用原位聚合法制备了聚酰亚胺/Al_2O_3纳米复合薄膜,将薄膜分别浸泡于高纯水中12、24、48、72、96、120、144、168 h,分析脉冲电压作用下浸水聚酰亚胺纳米复合薄膜的吸水性能和表面电荷分布动态特性,研究潮湿环境下聚酰亚胺/Al2O3纳米复合薄膜的绝缘破坏特性。结果表明:纳米复合薄膜的吸水率大于纯聚酰亚胺薄膜。与未添加纳米粒子的薄膜相比,浸水后纳米复合薄膜的表面电荷消散速度更快,击穿电压更低。由于吸水特性的影响,工作于潮湿环境中的纳米复合聚酰亚胺薄膜的耐击穿性会低于纯聚酰亚胺薄膜。

PI/Al2O3 nanocomposite films were prepared by in-situ polymerization method. The films were immersed in high purity water for 12, 24, 48, 72, 96, 120, 144, 168 h, and the water absorption and sur- face charge distribution characteristic of the films under impulse voltage were analyzed. The insulation breakdown characteristics of the PI/Al2O3 nanocomposite films in moist environment were studied. The results show that the water absorption of the nanocomposite films is higher than that of PI film. Com- pared with the PI film, the surface charge dissipation rate of the immersed nanocomposite films is faster, and the breakdown voltage is lower. Because of the effects of water absorption characteristic, the break- down resistance of the nanocomposite films is lower than that of PI film in moist environment.