▎ 摘　　要

NOVELTY - The preparation method of graphene oxide/crown ether composite modified polyimide film involves (i) dissolving aromatic diamine in an organic solvent, adding crown ether, stirring, adding aromatic dianhydride, stirring to obtain yellow viscous polyamic acid-crown ether solution, (ii) diluting polyamic acid-crown ether solution with organic solvent, adding into absolute ethanol, precipitating, filtering, removing the filtrate, adding into a vacuum oven, and drying to obtain yellow polyamic acid-crown ether composite inclusion. USE - Preparation of graphene oxide/crown ether composite modified polyimide film (claimed). ADVANTAGE - The preparation method of graphene oxide/crown ether composite modified polyimide film with low thermal expansion coefficient, and high tensile strength and break elongation rate. DETAILED DESCRIPTION - The preparation method of graphene oxide/crown ether composite modified polyimide film involves (i) dissolving aromatic diamine in an organic solvent, adding crown ether, stirring for 2-3 hours, where the ratio of crown ether and aromatic diamine is (0.1-0.4):1.0, adding aromatic dianhydride, stirring for 8-12 hours to obtain yellow viscous polyamic acid-crown ether solution, where the ratio of an aromatic dianhydride and an aromatic diamine is (1.0-1.1):1.0, (ii) diluting polyamic acid-crown ether solution with organic solvent, adding into absolute ethanol, precipitating, filtering, removing the filtrate, adding into a vacuum oven, and drying to obtain yellow polyamic acid-crown ether composite inclusion, (iii) dispersing polyvinylpyrrolidone and graphite oxide in an organic solvent in a ratio of (1~3):1, and ultrasonically treating at 100-400 W for 1-3 hours to obtain polyvinylpyrrolidone-graphene oxide dispersion, (iv) dissolving polyamic acid-crown ether solid inclusion in an organic solvent, adding polyvinylpyrrolidone-graphene oxide dispersion, stirring for 8-12 hours, uniformly applying to a clean glass, removing air bubbles, heating, drying, cooling to room temperature, removing the glass, immersing in hot water, and peeling off the film. An INDEPENDENT CLAIM is included for graphene oxide/crown ether composite modified polyimide film, which has thermal expansion coefficient of 23-35 ppm/K, tensile modulus of 3.2-3.9 GPa, tensile strength of 103-146 MPa, break elongation rate of 26-50%, and 5 wt.% loss temperature of 542-558 degrees C.