Graphene composite plastic and preparation method thereof

A graphene composite plastic for heat dissipation, comprising the following raw materials:

• 50%-60% of carrier resin, 30%-40% of modified graphene, 4%-7% of lubricant, 2%-4% of coupling agent and 3%-6% of stabilizer;
• wherein the modified graphene is prepared by the following method:
• S1, dissolving 20-30 mol of 1-vinyl-3-butyl imidazole tetrafluoroborate and 0.4-0.6 mmol of azobisisoheptonitrile into 600-800 mL of N,N-dimethylformamide, heating to 75-80° C. in an argon atmosphere, then condensing and refluxing, stirring for 20-24 h for polymerization reaction, adding 50-100 mL of acetone after the reaction is completed, centrifuging, filtering, and collecting precipitates to obtain a polymer;
• S2, dispersing 10-80 g of graphene into 30-40 L of N,N-dimethylformamide and performing ultrasonic treatment for 10-15 min, then adding 1-3 g of the polymer prepared in step S1 and performing ultrasonic treatment for 20-30 min, then adding 12-15 mg of azobisisoheptonitrile, heating to 65-75° C., reacting for 20-24 h, centrifuging after the reaction is ended, filtering, collecting solids, washing with water and then drying to obtain a graphene polymer;
• and
• S3, adding 10-12 L of water into the graphene polymer prepared in step S2, performing ultrasonic treatment for 25-30 min to obtain a graphene polymer suspension;
• dissolving 1.1-1.3 g of NaNO2 into 1.2-1.5 L of water, cooling to 0-5° C., adding 2.8-3.2 g of p-aminobenzenesulfonic acid and 50-80 mL of 0.5-1 mol/L HCl solution before mixing with the graphene polymer suspension, reacting for 2-3 h in ice water bath, reacting for another 2-3 h at room temperature, centrifuging for 5-8 min at 10000-12000 rpm after reaction is completed, washing the solid with water to neutral so as to obtain the modified graphene;
• wherein the carrier resin is a polypropylene resin.