▎ 摘　　要

NOVELTY - A composite material comprises 50-100 pts. wt. polylactic acid, 4-10 pts. wt. chitosan, 4-10 pts. wt. graphene nanosheet, 5-14 pts. wt. carbon fiber, 8-14 pts. wt. glass fiber, 6-12 pts. wt. talc, 1-5 pts. wt. silica sol, 12-18 pts. wt. expanded graphite, 2-6 pts. wt. attapulgite, 1-5 pts. wt. diaminodiphenylmethane tetraglycidylamine and 1-3 pts. wt. silane coupling agent. The graphene nanosheet is treated with diaminodiphenylmethane tetraglycidylamine, and has specific surface area of 80-100 m2/g. USE - Composite material. ADVANTAGE - The composite material has excellent high temperature resistance, flame retardant property, toughness and comprehensive mechanical strength. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for preparation method of composite material, which involves mixing graphene nanosheet and diaminodiphenylmethane tetraglycidylamine with dimethylformamide solvent and mechanically stirring at rotating speed of 500-1500 rpm for 1-3 hours, then placing in an drying oven and drying at 45-55 degrees C for 6 hours to obtain surface-modified graphene nanosheet, mixing surface-modified graphene nanosheet with polylactic acid, grinding the material in a three-roller grinder for 20-30 minutes to obtain graphene-polylactic acid mixture, mixing graphene-polylactic acid mixture with chitosan, talc, silane coupling agent, expanded graphite, attapulgite, silica sol and diaminodiphenylmethane tetraglycidylamine in a high mixing machine for 10-30 minutes, then adding carbon fiber and glass fiber and then placing in a twin-screw extruder, melt-blending and extruding, drying, cooling and blowing dry particles.