▎ 摘　　要

NOVELTY - The method for preparing graphene-modified porous polyimide composite material, involves placing graphene, polyimide powder and self-lubricating filler in oven, preparing coupling agent dilution solution, adding dry graphene to form graphene homogeneous dispersion, adding dried polyimide powder to treated graphene homogeneous dispersion to obtain graphene/polyimide mixture, grinding, adding graphene/polyimide composite powder and self-lubricating filler to prepare graphene modified polyimide composite powder, pressure molding and sintering to obtain final product. USE - Method for preparing graphene-modified porous polyimide composite material (claimed). ADVANTAGE - The economical method enables preparation of graphene-modified porous polyimide composite material with uniform porous structure, improved microporous uniformity, uniform internal structure, strength performance increased by 12-23%, friction coefficient decreased by 11-19%, wear and tear reduced by 18-48% and improved thermal conductivity. DETAILED DESCRIPTION - Method for preparing graphene-modified porous polyimide composite material, involves (S1) placing graphene, polyimide powder and self-lubricating filler in a blast oven at 110-130 degrees C for 4 hours, (S2) preparing 0.01-0.5 wt.% coupling agent dilution solution, adding 0.05-2 parts mass dry graphene, stirring at 2000 rpm for 12-24 hours to form graphene homogeneous dispersion, (S3) adding 98-99.95 parts mass dried polyimide powder to treated graphene homogeneous dispersion, stirring at 2000 rpm for 4-8 hours, removing solvent to obtain graphene/polyimide mixture, grinding and sifting using ball mill to obtain graphene/polyimide composite powder, (S4) adding 95-99 parts mass graphene/polyimide composite powder and 1-5 parts mass self-lubricating filler, mixing evenly to prepare graphene modified polyimide composite powder, (S5) transferring the composite powder into mold, preheating at 120-180 degrees C for 20-40 minutes, pressure molding at 1-50 MPa for 3-10 minutes, transferring the molded products into sintering furnace, sintering at 350-375 degrees C, heating at the rate of 3-5 degrees C/minute, insulating for 20-40 minutes, taking out, naturally cooling to room temperature and stripping to obtain final product.