▎ 摘　　要

NOVELTY - An environmentally-friendly flame-retardant polypropylene material comprises 100 pts. wt. polypropylene, 0.1-2 pts. wt. modified graphene, 0.5-3 pts. wt. modified carbon nanotubes, 10-20 pts. wt. inorganic flame retardant, 5-10 pts. wt. compatibilizer, 3-10 pts. wt. toughening agent, 0.1-0.3 pts. wt. antioxidant and 0.1-0.3 pt. wt. heat stabilizer. The modified graphene is prepared by uniformly dispersing an aqueous solution of a graphene powder with a coupling agent or a surfactant with a concentration of 0.1-10 mg/ mL, performing suction filtration, freeze-drying. USE - Environmentally-friendly flame-retardant polypropylene material (claimed). ADVANTAGE - The polypropylene material has high dispersibility in the polymer system, can effectively prevent the migration of combustibles in the polymer matrix, and has excellent flame retardant effect. DETAILED DESCRIPTION - An environmentally-friendly flame-retardant polypropylene material comprises 100 pts. wt. polypropylene, 0.1-2 pts. wt. modified graphene, 0.5-3 pts. wt. modified carbon nanotubes, 10-20 pts. wt. inorganic flame retardant, 5-10 pts. wt. compatibilizer, 3-10 pts. wt. toughening agent, 0.1-0.3 pts. wt. antioxidant and 0.1-0.3 pt. wt. heat stabilizer. The modified graphene is prepared by uniformly dispersing an aqueous solution of a graphene powder with a coupling agent or a surfactant with a concentration of 0.1-10 mg/ mL, performing suction filtration, freeze-drying where the coupling agent or surfactant accounts for 2-20% of the mass of the graphene and the graphene powder thickness is 0.5-5 nm. The modified carbon nanotubes are obtained by ultrasonically dispersing an aqueous solution of carbon nanotube powder with a coupling agent or a surfactant with concentration of 0.1-10 mg/mL, performing suction filtration, and freeze-drying where the coupling agent or surfactant accounts for 2-20% of the mass of the carbon nanotubes. The coupling agent is silane coupling agent or titanate coupling agent. The surfactant is long-chain alkyl amine, polyvinylpyrrolidone and/ polyvinyl alcohol. An INDEPENDENT CLAIM is included for method for preparing environmentally-friendly flame-retardant polypropylene material, which involves (i) preparing modified graphene by taking graphene powder with thickness of 0.5-5 nm, dissolving in deionized water to prepare graphene aqueous solution with concentration of 0.1-10 mg/mL, then adding coupling agent or surfactant for ultrasonic dispersion, evenly dispersing and then high-speed shear grinding to obtain modified graphene solution, where the coupling agent or surfactant accounts for 2-20% of the mass of graphene, (ii) preparing modified carbon nanotubes by dissolving carbon nanotubes powder in deionized water to prepare aqueous solution of carbon nanotubes with concentration of 0.1-10 mg/mL, then adding coupling agent or surfactant for ultrasonic dispersion, evenly dispersing and then high-speed shear grinding to obtain modified carbon nanotube solution where the coupling agent or surfactant accounts for 2-20% of the mass of the carbon nanotubes, (iii) mixing the solution obtained in step (i) and solution obtained in step (ii), ultrasonically dispersing, performing high-speed shear grinding so that carbon nanotubes are evenly distributed on the surface of graphene, adding inorganic flame retardant to the mixed solution, ultrasonically dispersing evenly, and performing high-speed shear grinding treatment, drying in a vacuum freeze-drying equipment to obtain modified flame retardant composite powder, (iv) adding modified flame retardant composite powder with a compatibilizer, toughening agent, antioxidant and heat stabilizer, stirring evenly, (v) adding the mixed material to the polypropylene master batch, stirring evenly, transferring into a twin-screw extruder for extrusion at 150-200 degrees C, granulating and then drying where the twin-screw extruder has screw speed of 10-40 rpm, feeding speed of 6-10 rpm and the speed of granulator is 120-200 rpm.