Study On The Structure And Properties Of Copolyimide/Modified Graphene Composite Film

This article uses polyimide as the basic material and graphene oxide as the nano-filler to prepare a variety of composite films,focusing on exploring the relationship between structure and performance,and aims to obtain polyimide films with high mechanical properties.The relationship between polyimide and monomer structure was first studied.By using2,2'-bis[4-(4-aminophenoxyphenyl)]propane as the monomer in the polymerization,a new type of high-performance PI film was obtained.The analysis results showed that the tensile strength increased from 96.9Mpa to 108.8Mpa when 50% 2,2'-bis[4-(4-aminophenoxyphenyl)]propane was added.At the same time,the polyimide film shows a certain degree of crystallization tendency and a unique structure.Through the ternary copolymerization modification,the comprehensive performance of the polyimide film was effectively improved.The blending method and the in-situ polymerization method were used in experiments to explore the relationship between the GO content and the properties of the composite film.Compared with the blending method,the in-situ polymerization method has more comprehensive performance,its tensile strength is increased to 164.9Mpa,and the thermal stability of the film is improved,when the graphene oxide content reaches 0.6%wt.Finally,through the reduction reaction of 2,6 Diaminopyridine and graphene oxide,amine modified graphene was obtained.According to the previous results,the composite film was prepared by in-situ polymerization and amine-modified graphene.Due to the special structure of diaminopyridine,amine-modified graphene helps to improve the imidization degree of polyimide and improve its performance.When the addition amount reaches 0.5%,the tensile strength of the composite film increases to 176.3Mpa,and the thermal stability increases.The result of DSC showed that Tg also increased by 15°C.And the calculation of FTIR results proves that the degree of imidization has increased.Finally,a high-performance polyimide composite film was successfully prepared.