▎ 摘　　要

NOVELTY - Graphene modified polyimide-based composite film comprises 95-105 pts. 4,4'-diaminodiphenyl ether (ODA), 110-120 pts. pyromellitic acid anhydride (PMDA) and 1-25 pts. graphene. USE - Used as a graphene modified polyimide-based composite film. ADVANTAGE - The composite has film density of 0.5-1.5 g/cm3 and tensile strength of 60-170 KJ/m2. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing the composite film, comprising: (i) adding ODA, graphene and solvent dimethylacetamide (DMAC) into reaction container, ultrasonically fully dissolving ODA, and completely dispersing graphene in DMAC to obtain graphene suspension, (ii) under the high speed stirring condition, adding graphene suspension into PMDA, increasing the amount of PMDA to increase the viscosity of system until the rod-climbing phenomenon is weak, and obtaining polyimide A pre-polymer of polyamic acid (PAA), continuously stirring for 3-10 hours, finishing diamine and dianhydride reaction completely to obtain graphene/PAA compound, where the stirring speed is 600-1500 revolutions per minute, (iii) laying the graphene/PAA compound on the flat smooth plate, leveling to obtain a composite film having uniform thickness, placing the plate on a ladder and heating at 80 degrees C, 120 degrees C, 180 degrees C, 240 degrees C and 300 degrees C, and insulating for 1-5 hours to obtain graphene composite film.