▎ 摘　　要

NOVELTY - A polyurethane composite material comprises 90-100 pts. wt. polyurethane, 5-10 pts. wt. composite filler, 1-5 pts. wt. functional material, 0.1-1 pt. wt. graphene quantum dots and porous graphene light stabilizer, 5-10 pts. wt. coupling agent, 0.1-2 pts. wt. leveling agent, 1-6 pts. wt. dispersing lubricant and 0.1-1 pt. wt. antioxidant. The functional material comprises nano silver/titania antimicrobial material, multi-walled carbon nanotube/nano-zinc oxide and aldehyde material. The composite filler comprises graphene/silicon dioxide composite filler and graphene/calcium carbonate. USE - Polyurethane composite material is used for graphene-modified reinforcing three-dimensional printing. ADVANTAGE - The polyurethane composite material has excellent antibacterial effect, flexibility and mechanical property. DETAILED DESCRIPTION - A polyurethane composite material comprises 90-100 pts. wt. polyurethane, 5-10 pts. wt. composite filler, 1-5 pts. wt. functional material, 0.1-1 pt. wt. graphene quantum dots and porous graphene light stabilizer, 5-10 pts. wt. coupling agent, 0.1-2 pts. wt. leveling agent, 1-6 pts. wt. dispersing lubricant and 0.1-1 pt. wt. antioxidant. The functional material comprises nano silver/titania antimicrobial material and multi-walled carbon nanotube/nano-zinc oxide in addition to an aldehyde material. The composite filler comprises graphene/silicon dioxide composite filler and graphene/calcium carbonate in a weight ratio of 3:2. The content of graphene quantum dots and porous graphene is 0.5-1 wt.% and 0.5-2 wt.%, respectively with respect to polyurethane. The polyurethane composite material is prepared by pretreating polyurethane raw materials by pulverizing polyurethane raw material into 300 mesh powder, dispersing in pure water, ultrasonically treating for 1 hour performing ultrasonic microwave irradiation for 1 hour, washing, discharging the resultant product, and drying, dispersing graphene/silica composite filler in pure water by ultrasonically stirring, obtaining a dispersion liquid (d1), dispersing graphene/calcium carbonate composite filler in pure water by ultrasonically stirring, obtaining a dispersion liquid (d2), heating, dissolving pretreated polyurethane in an organic solvent, obtaining a polyurethane solution, dividing into three, ultrasonically mixing portion (p1) of polyurethane solution at high speed at a constant temperature, dripping liquid (d1) in the resultant product, ultrasonically stirring for 30-60 minutes, dripping portion (p2) of the polyurethane solution, ultrasonically stirring for 30-60 minutes, dripping liquid (d2), ultrasonically stirring for 30-60 minutes, dripping portion (p3) of polyurethane solution, ultrasonically stirring for 30-60 minutes, dripping graphene quantum dot solution, ultrasonically stirring for 30-60 minutes, obtaining a polyurethane mixture, passing the polyurethane mixture into a storage tank of a spray dryer, spraying polyurethane mixture at a speed of 200-300 ml/minute, drying to obtain the polyurethane masterbatch (m1), dispersing functional materials in pure water by ultrasonically stirring, obtaining a functional material dispersion liquid, dispersing porous graphene in pure water by ultrasonically stirring, obtaining a porous graphene dispersion, dissolving 1/5 portion of pretreated polyurethane in an organic solvent to obtain a polyurethane solution, ultrasonically mixing, dripping functional material dispersion liquid in the resultant product, ultrasonically stirring for 30-60 minutes, dripping a portion of polyurethane solution in the resultant product, ultrasonically stirring for 30-60 minutes, dipping porous graphene dispersion in the resultant product, ultrasonically stirring for 30-60 minutes, obtaining a polyurethane mixture, passing the polyurethane mixture into a storage tank of a spray dryer, spraying polyurethane mixture at a speed of 200-300 ml/minute, drying to obtain the polyurethane masterbatch (m2), melt-mixing remaining pretreated polyurethane, masterbatch (m1), masterbatch (m2), light stabilizer, coupling agent, leveling agent, dispersion lubricant and antioxidant, adding to a mechanical grinding and pulverizing machine, pulverizing to obtain a polyurethane composite powder having an average particle size of 30-40 mu m, drying the resultant product at 95 degrees C for 2 hours, adding the dried powder to a twin-screw extruder, cooling to obtain a shaped wire, and winding.