▎ 摘　　要

NOVELTY - Preparation of modified graphene oxide-polyimide in-situ-grafted composite material involves preparing graphene oxide, preparing carboxylated graphene oxide, preparing aminated graphene oxide using carboxylated graphene oxide, dispersing aminated graphene oxide in N,N'-dimethylacetamide and 4,4'-diaminodiphenyl ether, stirring, adding 1,2,4,5-pyromellitic dianhydride, stirring, pouring graphene oxide-polyamide composite material into flat-bottomed glass vessel, evaporating solvent, gradually heating and cooling. USE - Preparation of modified graphene oxide-polyimide in-situ-grafted composite material (claimed). ADVANTAGE - The method enables preparation of modified graphene oxide-polyimide in-situ-grafted composite material having high dielectric constant, and excellent thermal performance, mechanical property and dielectric property. DETAILED DESCRIPTION - Preparation of modified graphene oxide-polyimide in-situ-grafted composite material involves preparing graphene oxide by adding 2 parts mass nano-graphite, 1 part mass sodium nitrate and 85 parts mass concentrated sulfuric acid to a reactor, stirring in ice-water bath, cooling reactor to less than 5 degrees C, slowly adding 6 parts mass potassium permanganate to the resultant product, heating to 35 degrees C for 30 minutes, dripping 100 parts mass deionized water in the resultant product, heating to 98 degrees C for 15 minutes, successively adding 300 parts mass deionized water and 22 parts mass 30 %mass hydrogen peroxide, filtering the resultant product while hot, washing using deionized water to neutral and drying in vacuum at 60 degrees C, preparing carboxylated graphene oxide by adding 1 part mass graphene oxide and 300 parts mass deionized water in a reactor, ultrasonically treating, adding 75 parts mass hydrobromic acid, stirring for 24 hours, adding 21 parts mass oxalic acid to reactor, stirring for 24 hours, filtering, washing with deionized water to neutral and drying the resultant product in vacuum at 60 degrees C, preparing aminated graphene oxide by ultrasonically-dispersing 1 part mass carboxylated graphene oxide and 1 part mass N,N'-dicyclohexylcarbodiimide in 936 parts mass N,N'-dimethylacetamide, stirring for 4 hours, adding 1 part mass p-phenylenediamine, stirring in nitrogen or argon atmosphere for 24 hours, filtering, washing the resultant product with ethanol and drying in vacuum at 60 degrees C, dispersing aminated graphene oxide in 18.8 parts mass N,N'-dimethylacetamide and 1 part mass 4,4'-diaminodiphenyl ether, stirring to dissolve, adding 1.1 parts mass 1,2,4,5-pyromellitic dianhydride four times to reactor, stirring for 4 hours, pouring graphene oxide and polyamide composite material into flat-bottomed glass vessel, evaporating solvent at room temperature, gradually heating to 400 degrees C in muffle furnace, cooling the resultant product to room temperature, and obtaining composite material having graphene-polymer-graphene layer structure.