表面氟化对潮湿环境下聚酰亚胺薄膜绝缘性能以及表面电荷动态特性影响的研究

Effects of Surface Fluorination on Insulating Properties and Surface Charge Dynamic Characteristics of Polyimide Film in Moist Environment

为增强聚酰亚胺薄膜在潮湿环境中的绝缘性能,基于聚合物表层分子结构改性技术对聚酰亚胺薄膜进行表面氟化处理15、30、45、60 min,并将其浸泡于高纯水中6、12、24 h,比较氟化前后聚酰亚胺薄膜的吸水性能和表面电荷消散特性,分析表面氟化时间对聚酰亚胺薄膜吸水特性的影响机理以及氟化、吸水共同作用下表面电荷动态特性变化机理。结果表明:氟化处理聚酰亚胺薄膜的吸水率小于未氟化聚酰亚胺薄膜。浸水的氟化聚酰亚胺薄膜的表面电荷消散时间比未氟化聚酰亚胺薄膜的长,击穿电压比未氟化聚酰亚胺薄膜的高。证明表面氟化是一种增强聚酰亚胺薄膜在潮湿环境中耐受能力的一种有效方法。

In order to enhance the insulating properties of polyimide （PI） film in moist environment, PI films were fluorinated for 15, 30, 45 and 60 min, and then were immersed in high purity water for 6, 12 and 24 h, respectively. The water absorption and surface charge dissipation properties of the PI films before and after fluorination were measured, and the influence mechanism of surface fluorination time on the water absorption of PI films and the variation mechanism of surface charge dynamic characteristics under the effect of fluorination and water absorption were analyzed. The results show that the water absorption of the fluorinated samples is lower than that of the unfluorinated samples. The surface charge dissipation time of the fluorinated samples in moist environment is longer than that of the unfluorinated samples, and the breakdown voltage is higher than that of the unfluorinated samples. The research proves that the surface fluorination is an effective method to enhance the moisture tolerance of PI films.