表面氟化聚酰亚胺薄膜的空间电荷动态特性研究（英文）

Space Charge Behavior in Direct-fluorinated Polyimide Films

聚酰亚胺以其优良的电气性能作为一种重要的绝缘介质在工业领域得到了广泛的应用。由于温度能够显著影响绝缘介质的老化程度,对不同温度条件下聚酰亚胺薄膜的空间电荷分布开展研究具有重要的意义。最近的研究表明,表面氟化技术能够在不破坏聚酰亚胺薄膜内部分子结构的前提下改变其表层分子结构从而进一步提高其电气性能。通过对聚酰亚胺进行不同条件下改性处理,制备了4组试验试样,每组样品为两层聚酰亚胺叠加以研究其界面空间电荷分布。所用试样表面氟化处理时间分别为15 min、45 min和75 min。搭建了基于激光热脉冲法的空间电荷测量装置,分别测量了40℃、80℃、120℃、160℃下试样的空间电荷分布。结果表明表面氟化处理技术能够调节聚酰亚胺薄膜间空间电荷分布,且随着温度的提高聚酰亚胺内部积聚的空间电荷变少。

Polyimide film has excellent electrical properties and it serves as an important insulating material which is widely used in different industry fields.Since high temperature is a significant reason for degradation in insulation,the space charge distributions of polyimide （PI） films in high temperature condition is worth investigating.Previous studies found that surface fluorination could modify the surface layer properties of polyimide.In this paper,to investigate how space charges behave in bistratal PI film, double-layered samples were prepared for the experiment.The samples were made by one piece of non- fluorinated original or corona-resistant PI film and one piece of original or corona-resistant PI film which were surface- fluorinated for 15 min,45 min and 75 rain respectively.In the experiment,the charge injecting process was held under 40℃ ,80℃, 120℃and 160 ℃.In order to present the distributions of space charge in the 25 μm thick samples,a laser-induced thermal pulse measurement was set up.Results show that the space charges at the interface can be modulated with different fluorination time ,and with the rising of the temperature ,fewer space charges accumulate in the bistratal samples.