▎ 摘　　要

NOVELTY - Manufacture of reduced graphene oxide coated carbon fiber reinforced nylon 12 composite material involves (i) mixing carbon fiber and concentrated nitric acid, heating to 120°C, maintaining for 8 hours, diluting, filtering, cooling to room temperature, washing repeatedly until neutral, drying in vacuum before use, (ii) dissolving shellac flakes in isopropanol solution, stirring in a water bath at 60°C for 1 hour, and ultrasonically treating for 0.5 hour to fully dissolve shellac in isopropanol solution to obtain shellac solution, (iii) stirring the pretreated carbon fiber and the shellac solution evenly, transferring the solution to 65°C oven to dry for 12 hours, annealing the dried composite material and grinding, and (iv) adding the obtained composite material and nylon particles into absolute ethanol, adding calcium stearate and antioxidant simultaneously, transferring to a reactor, heating, washing with deionized water, suction filtering, drying, and grinding. USE - Manufacture of reduced graphene oxide coated carbon fiber reinforced nylon 12 composite material used for MJR 3D printing (claimed) for aerospace application, sports and leisure product, automobile application, and wind power generation blade. ADVANTAGE - The prepared reduced graphene oxide coated carbon fiber reinforced nylon 12 composite material has excellent mechanical strength, tensile strength and impact strength, and improved interface bonding strength between the substrate with the reduced graphene oxide coating and the carbon fiber. DETAILED DESCRIPTION - Manufacture of reduced graphene oxide coated carbon fiber reinforced nylon 12 composite material involves (i) mixing carbon fiber and concentrated nitric acid, heating to 120°C, maintaining for 8 hours, diluting, filtering, cooling to room temperature, washing repeatedly until neutral, drying in vacuum before use, (ii) dissolving shellac flakes in isopropanol solution, stirring in a water bath at 60°C for 1 hour, and ultrasonically treating for 0.5 hour to fully dissolve shellac in isopropanol solution to obtain shellac solution, (iii) stirring the pretreated carbon fiber and the shellac solution evenly, transferring the solution to 65°C oven to dry for 12 hours, annealing the dried composite material and grinding, and (iv) adding the obtained composite material and nylon particles into absolute ethanol, adding calcium stearate and antioxidant simultaneously, transferring to a high-temperature and high-pressure reactor, after the temperature changes from room temperature to 150°C, vigorously stirring and maintaining warm for 2 hours, lowering the temperature rapidly to 110°C to make nylon 12 nucleate in heterogeneous phases with composite material as the core, and finally washing with deionized water, suction filtering, drying, and grinding. An INDEPENDENT CLAIM is included for usage method for the reduced graphene oxide coated carbon fiber reinforced nylon 12 composite material for MJR three-dimensional (3D) printing, which involves using the reduced graphene oxide coated carbon fiber reinforced nylon 12 composite material for MJR 3D printing, selectively spraying flux on the powder layer, according to the layer printing data, and after infrared light, absorbing the infrared light by the flux and converting it into heat, so that the composite material is melted and shaped, after the first layer is printed, lowering powder bed by one layer, repeating powder spreading, preheating, and flux injection to print the second layer, to finally print the required 3D printing sample strip.