▎ 摘　　要

NOVELTY - Graphene in situ modified polylactam composite material is claimed. USE - Graphene in situ modified polylactam composite material is used in laser selection sintering area (claimed). ADVANTAGE - The composite material has tensile strength of 60-100 MPa, impact strength of 90-170 J/m, volume wear rate of (1-5)x 105mm3 N/m (claimed), has good dispersibility, good compatibility, stable performance and characteristics, can achieve size stability, has anti-wear property and obvious toughness. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing graphene in situ modified polylactam composite material comprising (i) taking graphite, sodium nitrate, sulfuric acid separately in a container and stirring for 5-20 minutes, adding potassium permanganate, room temperature reacting for 10-30 minutes, adding deionized water and hydrogen peroxide, at 40-110 degrees C, stirring, refluxing reacting for 5-10 hours, carrying out hot heat suction filtration, washing filter liquor to neutral, taking obtained product graphene oxide, and drying, (ii) adding step (i) product in dimethylformamide and dispersant, ultrasonic dispersing for 1-3 hours, adding isocyanate, stirring, reacting for 3-6 hours, filtering and dimethylformamide extraction for 6-12 hours, obtaining modified isocyanate and graphene oxide, (iii) taking isocyanate and modified graphene, dispersing in dimethylformamide and oxidizing, adding lactam monomer, stirring and heating to 100-130 degrees C, reacting for 3-6 hours after filtering, extracting for 6-12 hours with dimethylformamide, drying, obtaining beta -terminated modified graphene oxide, and (iv) capping and graphene oxide and lactam monomer mixture, where the temperature for ultrasonic treatment is 100-120 degrees C constant temperature condition of 3-6 hours, at 130-140 degrees C, adding catalyst, vacuumizing for 10-30 minutes, adding isocyanate, stirring uniformly, at 140-170 degrees C, polymerizing, maintaining the temperature for 20-60 minutes to obtain graphene material modified polylactam composite material.