▎ 摘　　要

NOVELTY - Preparing polyimide film involves taking molar ratio of dianhydride and diamine as 1: 1 under protection of nitrogen. The aromatic dianhydride is added into the aromatic diamine solution in batches to obtain polyamide with solid content of 10-20% polyamic acid solution. The nano-graphene is added to the polyamic acid solution and dispersed uniformly using an ultrasonic disperser. 0.4-0.8% graphene is added of the total mass of the solid in the A solution. USE - Method for preparing polyimide film (claimed) used as high heat dissipation material. ADVANTAGE - The method enables to prepare polyimide film, which has high thermal conductivity and z-axis thermal conductivity. DETAILED DESCRIPTION - Preparing polyimide film involves taking molar ratio of dianhydride and diamine as 1: 1 under protection of nitrogen. The aromatic dianhydride is added into the aromatic diamine solution in batches to obtain polyamide with solid content of 10-20% polyamic acid solution. The nano-graphene is added to the polyamic acid solution and dispersed uniformly using an ultrasonic disperser. 0.4-0.8% graphene is added of the total mass of the solid in the A solution. The reaction device temperature is reduced to -20 degrees C to 0 degrees C and adding imidization dehydrating agent and catalyst stirring to obtain B solution. The B solution is casted onto a stainless steel plate and drying the gel film. The gel film is stripped from the stainless steel plate and fixed in a metal frame and placed in an imine furnace for imidization and then heat-setting to obtain polyimide film.