Progress on Research of Thermal Oxidation Stability of Polyimide Films

In recent years, polyimide has been widely used in high temperature devices, so higher requirements are put forward for temperature resistance of materials. Polyimide in the high temperature environment above 300 ℃ will occur thermal oxygen aging, resulting in the deterioration of material properties. In this paper, the mechanism of thermo- oxygen aging of polyimide films and modification method were introduced. Firstly, the molecular structure modification of polyimide was introduced, and the methods of introducing rigid structures such as benzimidazole and benzooxazole into the chain segments to improve the thermal stability of polyimide films were summarized. Secondly, the modification of filler blend was introduced, and the thermal stability of PI films is further improved by introducing layered silicates, carbides or metal oxides and hybrid of high thermal conductivity filler. The research progress and development status of thermal oxidation stability of surface modified and coating modified PI films at home and abroad were briefly introduced. Finally, the future development directions of PI film with high temperature resistance and high thermal conductivity were summarized and prospected. © 2024 Sichuan University. All rights reserved.