▎ 摘　　要

NOVELTY - Preparing nylon composite engineering plastic involves uniformly dispersing carboxylated graphene in an organic solvent to obtain a graphene liquid, mixing graphene solution, 5-aminoisophthalic acid and triphenyl phosphite, heating to 90-120 degrees C for 0.6-2 hours under the protection of nitrogen or inert gas, raising temperature to 140-160 degrees C, adding glass fiber, continue to react for 0.6-2 hours, stop inerting gas or nitrogen, adding acetic acid, evacuating, and reacting under vacuum for 0.3-1 hours to obtain the pre-product. The pre-product is put in a vacuum drying box for 10-18 hours for solid-phase polymerization to obtain hyperbranched polyamide/glass fiber composite material. The molar ratio of carboxylated graphene, 5-aminoisophthalic acid, triphenyl phosphite, glass fiber and acetic acid is 0.1-0.5: 1-3: 2-6: 0.5-0.8: 10-15. USE - Method for preparing nylon composite engineering plastic for railway tracks. ADVANTAGE - The method enables to prepare nylon composite engineering plastic, which has high compression strength and good abrasion resistance. DETAILED DESCRIPTION - Preparing nylon composite engineering plastic involves uniformly dispersing carboxylated graphene in an organic solvent to obtain a graphene liquid, mixing graphene solution, 5-aminoisophthalic acid and triphenyl phosphite, heating to 90-120 degrees C for 0.6-2 hours under the protection of nitrogen or inert gas, raising temperature to 140-160 degrees C, adding glass fiber, continue to react for 0.6-2 hours, stop inerting gas or nitrogen, adding acetic acid, evacuating, and reacting under vacuum for 0.3-1 hours to obtain the pre-product. The pre-product is put in a vacuum drying box for 10-18 hours for solid-phase polymerization to obtain hyperbranched polyamide/glass fiber composite material. The molar ratio of carboxylated graphene, 5-aminoisophthalic acid, triphenyl phosphite, glass fiber and acetic acid is 0.1-0.5: 1-3: 2-6: 0.5-0.8: 10-15. The hyperbranched polyamide/glass fiber composite material, nylon 66, toughening agent, antioxidant and flame retardant are mixed, and then extruded and granulated through a twin-screw extruder to obtain a wear-resistant for railway tracks Nylon composite engineering plastic.