Study On Film-Forming Properties Of Polyimide/Graphite Composites

For the overall performance of outstanding mechanical properties,thermal stability,low dielectric properties and chemical resistance,Polyimide(PI)have been widely used in microelectronics,membranes,coatings,aerospace and adhesives etc.fields.With the improvement of the application requirements of materials,the preparation of high performance,multi-functional polyimide has become an important research direction.Graphene is a new carbon material.Graphene has excellent optical,electrical,thermal and mechanical properties for its unique two-dimensional monolayer structure.Therefore,graphene get greate concerned from it is discovered.The development of various types of graphene nanocomposites has also become a hot research topic.In this paper,polyimide and polyimide / graphene composite sections were used as raw materials.First,the performance of the two kinds of raw materials was tested and analyzed.Then,the film forming method and film forming process of the two kinds of raw materials were explored.Finally,the properties of the two films of polyimide and polyimide / graphene were tested and compared.And the effects of the addition of graphene on the structural properties of polyimide films were investigated.The main results of this paper are as follows:(1)By FTIR analysis,it can be seen that the raw materials used in the experiment were uniminated polyamic acid and its composite materials.The addition of graphene resulted in the absorption of the matrix polymer at 1219 cm-1 and 1243 cm-The TG and DSC tests show that the addition of graphene does not have a significant effect on the thermal properties of the raw material slices.(2)The optimum solution for the slices was N-methylpyrone,and the optimum solid content of the solution was 18%.The direct drying method was better than the direct drying method.(3)By comparing the properties of polyimide and polyimide / graphene composites at different heat treatment temperatures,it was found that the polyimide characteristic peaks appeared in the infrared spectrum of the samples after overheating,The characteristic peaks of the films after heat treatment were the most obvious,but the addition of graphene did not affect the imidization process of polyimide and the functional groups of polyimide.XRD showed that the addition of graphene did not affect the polyimide(UV-Vis)showed that the graphene particles were distributed on the surface of the polyimide film,and the results showed that the polyimide / The contact angle of polyimide / graphene film is larger than that of pure polyimide film,and the contact angle of polyimide / graphene film is larger than that of pure polyimide film.Indicating that the addition of graphene makes the polyimide have better hydrophobic properties.Through the mechanical properties analysis,can be obtained by adding graphene polyimide,can improve its tensile strength;through the thermal properties(DSC)analysis,the glass transition temperature of polyimide / graphene composites is greatly improved.