▎ 摘　　要

NOVELTY - Preparing graphene polyimide composite film involves mixing 1 pts. wt. graphene through grinding and dispersing, uniformly disperses 9 pts. wt. dimethyl acetamide in a solvent, then adding 1 pts. wt. polyamic acid in the suspension, continuously dispersing to form graphene suspension, dissolving the diamine of 4,4-diaminodiphenyl ether and second binary anhydride of pyromellitic dianhydride in the dimethyl acetamide solvent, then conducting polycondensation reaction to form polyamic acid, recycling dispersing, de-foaming the casting film-forming polymer, imidizing, rolling and cutting. USE - For preparing graphene polyimide composite film (claimed). ADVANTAGE - The prepared graphene polyimide composite film has the stretching intensity of not less than 100 Mpa; has the thermal conductivity of not less than 5 w/m.k; and has elongation at break of not less than 15%. DETAILED DESCRIPTION - Preparing graphene polyimide composite film include using graphene and 4,4-diaminodiphenyl ether and pyromellitic dianhydride in a solvent in the condensation polymerization of polyamic acid, involves mixing 1 pts. wt. graphene through grinding and dispersing, where the dispersed particle has diameter of less than or equal to 100 m, uniformly dispersing 9 pts. wt. dimethyl acetamide in a solvent, then adding 1 pts. wt. polyamic acid in the suspension, continuously dispersing to obtain graphene suspension, dissolving the diamine of 4,4-diaminodiphenyl ether and a second binary anhydride of pyromellitic dianhydride in the dimethyl acetamide solvent, where the amine and anhydride having mol ratio of 1:0.80 to 1:0.90, then conducting polycondensation reaction to form polyamic acid, recycling dispersing for 10-16 hours, where the acid and anhydride having mol ratio of 1: 0.98 to 1: 0.995, the viscosity is adjusted to 60000-90000 CP, where the polyamic acid of graphene in the solid content is 1-15%; de-foaming the casting film-forming polymer, conducting imidization, rolling and cutting to obtain the product.