▎ 摘　　要

NOVELTY - Preparing graphene graft modified hyperbranched polyimide dielectric material, comprises e.g. (i) pouring nitrogen into three-necked flask to exhaust the air, adding N,N-dimethylformamide solution and graphene oxide, performing ultrasonic dispersion, adding n-butyl lithium solution, and performing ultrasonic activation reaction for 1-2 hours, (ii) adding epichlorohydrin to the activated graphene oxide solution, performing a nucleophilic substitution reaction, centrifuging to remove the solvent, and washing the solid product with distilled water and acetone to obtain graphene epoxide, and (iii) pouring nitrogen into the three-necked flask to exhaust the air, adding N,N-dimethylacetamide solvent, 1,3,5-tris(4-aminophenyl) benzene and dianhydride monomers for hyperbranching in the polymerization reaction, placing three-necked flask in an ice-water bath to cool, adding methanol solvent for precipitation, filtering the solvent, and washing the product with methanol. USE - The method is useful for preparing graphene graft modified hyperbranched polyimide dielectric material. ADVANTAGE - The method: polymerizes dianhydride monomer to generate amino-terminated polyamic acid precursor; utilizes active terminal amino group to undergoe a ring-opening addition reaction with the epoxy group of graphene; enhances the compatibility and interface adhesion between the two; overcomes the problem of agglomeration and agglomeration, graphene nanoparticles and polyimide form an interface polarization phenomenon; improves the polarization intensity in the system; builds a stable seepage system; increases dielectric constant of polyimide; improves the dielectric loss; and prepared with excellent dielectric properties. DETAILED DESCRIPTION - Preparing graphene graft modified hyperbranched polyimide dielectric material, comprises (i) pouring nitrogen into the three-necked flask to exhaust the air, adding N,N-dimethylformamide solution and graphene oxide, performing ultrasonic dispersion, adding n-butyl lithium solution, and performing ultrasonic activation reaction for 1-2 hours, (ii) adding epichlorohydrin to the activated graphene oxide solution, performing a nucleophilic substitution reaction, centrifuging to remove the solvent, and washing the solid product with distilled water and acetone to obtain graphene epoxide, (iii) pouring nitrogen into the three-necked flask to exhaust the air, adding N,N-dimethylacetamide solvent, 1,3,5-tris(4-aminophenyl) benzene and dianhydride monomers for hyperbranching in the polymerization reaction, placing three-necked flask in an ice-water bath to cool, adding methanol solvent for precipitation, filtering the solvent, washing the product with methanol, and preparing an amino-terminated polyamic acid precursor, (iv) adding N,N-dimethylacetamide solvent, amino-terminated polyamic acid precursor and epoxidized graphene to the three-necked flask to perform an addition reaction, cooling the solution, precipitating with methanol, filtering and washing, and preparing graphene grafted polyamic acid precursor, and (v) placing graphene grafted polyamic acid precursor in an oven, and performing thermal imidization.