▎ 摘　　要

NOVELTY - Preparing graphene reinforced polyimide composite film comprises e.g. stirring to react potassium permanganate, reducing residual oxidant using hydrogen peroxide to obtain bright yellow solution, filtering, washing filter cake using diluted hydrochloric acid, water, and polar organic solvent to fully remove moisture to obtain graphene oxide precursor, placing obtained graphene oxide precursor in polar organic solvent, adding polyamine/amino dispersant, mechanically dispersing to combine active groups on graphene oxide precursor surface with polyamine/amino dispersant to obtain homogeneous functionalized graphene oxide precursor solution, adding homogeneous functionalized graphene oxide precursor solution, aromatic diamine, and aromatic dianhydride to polar non-proton solvent, synthesizing graphene oxide reinforced polyamic acid resin solution, preparing graphene oxide reinforced polyamic acid resin solution by conventional process to obtain graphene reinforced polyimide composite film. USE - The method is useful for preparing graphene reinforced polyimide composite film. ADVANTAGE - The composite film has improved mechanical and electrical properties. The graphene oxide precursor solution has good stability. The grain has suitable nanometer level, and high oxidation degree. The artificial graphite film has no cracks, no curling, and good appearance. DETAILED DESCRIPTION - Preparing graphene reinforced polyimide composite film comprises (i) preparing graphene oxide precursor using Hummers' method including stirring to react potassium permanganate for 0.5-5 hours, controlling stirring speed at 300-1800 revolutions/minute, raising temperature to 35 degrees C to react, reducing residual oxidant using hydrogen peroxide to obtain bright yellow solution, filtering, and washing filter cake using diluted hydrochloric acid, water, and polar organic solvent to fully remove moisture to obtain graphene oxide precursor, (ii) placing obtained graphene oxide precursor in polar organic solvent, adding polyamine/amino dispersant, and mechanically dispersing to combine the active groups e.g. carboxy groups and hydroxy groups on graphene oxide precursor surface with polyamine/amino dispersant to obtain homogeneous functionalized graphene oxide precursor solution, where the amine/amino functionality of polyamine/amino dispersant is greater than or equal to 2 with heat resistance of less than or equal to 220 degrees C, and the adding amount of polyamine/amino dispersant is 1-10% of weight of graphene oxide precursor, (iii) adding homogeneous functionalized graphene oxide precursor solution, aromatic diamine, and aromatic dianhydride to polar non-proton solvent, and synthesizing graphene oxide reinforced polyamic acid resin solution by in-situ method, where the adding amount of homogeneous functionalized graphene oxide precursor solution is to control graphene oxide in graphene oxide reinforced polyamic acid resin solution with a solid content of 0.05-2 wt.%, and (iv) preparing graphene oxide reinforced polyamic acid resin solution by conventional process to obtain graphene reinforced polyimide composite film. INDEPENDENT CLAIMS are also included for: (1) the graphene reinforced polyimide composite film; (2) preparation of artificial graphite film comprising (1) heating graphene reinforced polyimide composite film at 500-650 degrees C under vacuum condition for at least two times, each time thermally insulating for greater than or equal to 0.5 hours, raising temperature to not greater than 1600 degrees C, and finishing carbonization treatment to obtain carbonized polyimide film, and (2) performing graphitization of carbonized polyimide film at greater than or equal to 2600 degrees C to obtain artificial graphite film; and (3) the artificial graphite film.