▎ 摘　　要

NOVELTY - The preparation method of graphene/polyimide composite material involves placing graphite powder, sodium nitrate and concentrated sulfuric acid into a beaker, stirring, adding potassium permanganate to the beaker, continuously stirring, heating, stirring, heating, continuously stirring, filtering, washing, and drying to obtain solid graphite oxide, dissolving graphite oxide in water, ultrasonically processing, leaving still, ultrasonically processing, centrifuging, and taking supernatant to obtain graphene oxide dispersion liquid, and adjusting the pH value of dispersion liquid. USE - Preparation method of graphene/polyimide composite material. ADVANTAGE - The method enables preparation of graphene/polyimide composite material with high hardness and excellent corrosion resistance. DETAILED DESCRIPTION - The preparation method of graphene/polyimide composite material involves (1) placing graphite powder, sodium nitrate and concentrated sulfuric acid into a beaker, stirring at 0-5 degrees C for 10-20 minutes, adding potassium permanganate to the beaker, continuously stirring for 10-20 minutes, where the mass ratio of graphite powder, sodium nitrate and potassium permanganate is (1-3):(1-3):(4-10), heating at 30-50 degrees C, stirring and reacting for 1-2 hours, heating at 85-100 degrees C, continuously stirring and reacting for 0.5-1.5 hours, filtering, washing with deionized water 3-5 times, and drying to obtain solid graphite oxide, dissolving graphite oxide in water, ultrasonically processing for 20-60 minutes, leaving still for 10-20 hours, ultrasonically processing for 20-60 minutes, centrifuging, and taking supernatant to obtain graphene oxide dispersion liquid, (2) adjusting the pH value of the graphene oxide dispersion liquid obtained in step (1) to 9-11, adding p-phenylenediamine, stirring for 10-20 minutes, heating at 90-100 degrees C, continuously stirring for 5-8 hours, filtering, washing 3-5 times using ethanol, and naturally drying to obtain modified graphene oxide, (3) adding the modified graphene oxide obtained in the step (2) to hydrochloric acid solution, ultrasonically stirring for 20-60 minutes, adding imide, stirring for 20-60 minutes, adding ammonium persulfate, continuously stirring for 1-6 hours, filtering, washing 3-5 times using ethanol, placing the filter residue after washing in the mixed solution of aqueous ammonia and deionized water, stirring for 3-6 hours, filtering, washing 3-5 times using ethanol, and drying the filter residue at 50-80 degrees C for 15-24 hours to obtain modified graphene oxide/polyimide composite material, and (4) dissolving the modified graphene oxide/polyimide composite material obtained in the step (3) with 1-methyl-2-pyrrolidone, stirring for 10-30 hours, adding polystyrene, continuously stirring for 1-3 hours, and leaving still.