▎ 摘　　要

NOVELTY - Preparing high temperature resistant polyimide comprises (1) mixing and stirring 30-40 pts. wt. imidazole diamine, 40-50 pts. wt. biphthalic anhydride, 5-10 pts. wt. polycaprolactone, 10-20 pts. wt. 2-(4-aminophenyl)-5-aminobenzimidazole, 0.5-5 pts. wt. graphene and organic solvent evenly to form a polyamic acid resin solution, and the mass-volume ratio of the raw material and the organic solvent is 1:10-15, (2) carrying out suction filtration and vacuum defoaming of polyamic acid resin solution, and casting on a casting plate, and solidifying into an adhesive film, and (3) heating film to 400-480℃ in stages for every 30-80℃, residence time at the end of each temperature section is 3-15 minutes, and cooling. USE - The method is useful for preparing high temperature resistant polyimide, which is useful for manufacturing flexible display substrate as substitute material of glass. ADVANTAGE - The polyimide: has low thermal expansion, low moisture absorption rate, high thermal resistance and high toughness.