▎ 摘　　要

NOVELTY - Three-dimensional (3D) heat conducting needled felt polyamide composite material comprises chopped fiber, graphene oxide solution, 5-10 wt.% 3D thermal conductive needle felt preform made of nylon 6 monomer and initiator and 90-95 wt.% polyamide. USE - The material is useful in the field of heat dissipation. ADVANTAGE - The method adopts the thermal reduction reaction that occurs during in situ polymerization, which enhances the thermal conductivity of the 3D structure formed by the needle felt with surface modified graphene, increases the interaction between polar functional groups, makes the 3D structure compatible with the interface of polymer materials, thus the prepared material has good mechanical and thermal conductivity properties. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing composite material comprising (a) mixing nylon 6 monomer and initiator, ultrasonically dispersing and stirring at 70-80 degrees C for 0.5-1 hour to form a premix, (b) vacuum injecting the prepared premix into a three-dimensional thermal conductive needle felt preform, drying for 0.5-2 hours, prepolymerizing at 150-180 degrees C for 1-4 hours to form a prepolymer, (c) polymerizing the prepolymer at 220-250 degrees C under nitrogen protection for 1-10 hours, performing reduced pressure operation before the end of the polymerization to maintain the vacuum inside the system and (d) obtaining the composite material after the polymerization is completed.