▎ 摘　　要

NOVELTY - Composite material comprises 50-100 pts. wt. polylactic acid, 4-10 pts. wt. chitosan, 2-8 pts. wt. graphene nanosheets, 5-15 pts. wt. carbon fiber, 8-16 pts. wt. glass fibers, 5-10 pts. wt. wollastonite, 1-5 pts. wt. silica sol, 1-5 pts. wt. diaminodiphenylmethane tetraglycidylamine and 1-3 pts. wt. silane coupling agent. The specific surface area of the graphene nanosheet reaches 80-100m2/g and is treated with diaminodiphenylmethane tetraglycidylamine. USE - Composite material. ADVANTAGE - The composite material has good toughness and high temperature resistance, and high comprehensive mechanical strength. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for a method for preparing composite material, which involves: (A) mixing graphene nanosheets in a dimethylformamide solvent together with diaminodiphenylmethane tetraglycidylamine, mechanically stirring for 1-3 hours at a rotation speed of 500-1500 revolution per minute (rpm), uniformly, and drying oven at 45-55 degrees C for 6 hours to obtain a surface-modified graphene nanosheet; (B) mixing the surface-modified graphene nanosheet with the polylactic acid particles uniformly and crushing in a three-roll mill for 20-30 minutes to obtain a polylactic acid graphene mixture; (C) mixing the polylactic acid graphene mixture with chitosan, wollastonite powder, silane coupling agent, silica sol, and diaminodiphenylmethane tetraglycidylamine in the high-mixer for 10-30 minute, and then adding to the hopper of the twin-screw extruder to obtain composite; and (D) adding carbon fiber and glass fiber into obtained composite and subjecting into twin-screw extruder at a certain ratio, melt-blend extrusion is used to extrude the material, and cooling to obtain composite material.