▎ 摘　　要

NOVELTY - Modified enhanced antibacterial polyurethane composite material comprises e.g. polyurethane, inorganic filler, graphene/titanium dioxide cleaning material, multi-walled carbon nanotube/nano-silver antimicrobial material, graphene quantum dots and porous graphene, light stabilizer, coupling agent, leveling agent, dispersing lubricant and antioxidant, where the ratio of graphene/titanium dioxide cleaning material and multi-walled carbon nanotubes/nano-silver antibacterial material is 2-3:1-3. USE - The material is useful for three dimensional printing (claimed). ADVANTAGE - The material has good properties of flexibility and excellent mechanical properties, self-cleaning and anti-fouling properties, Further broadening the scope of application of 3D printing. DETAILED DESCRIPTION - Modified enhanced antibacterial polyurethane composite material comprises 90-100 pts. wt. polyurethane, 5-10 pts. wt. inorganic filler, 0.5-1 pts. wt. graphene/titanium dioxide cleaning material, 0.5-1 pts. wt. multi-walled carbon nanotube/nano-silver antimicrobial material, 0.1-1 pts. 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 pts. wt. antioxidant, where the ratio of graphene/titanium dioxide cleaning material and multi-walled carbon nanotubes/nano-silver antibacterial material is 2-3:1-3, the amount of graphene quantum dots is 0.5-1 wt.% of polyurethane, the amount of porous graphene is 0.5-2 wt.% of polyurethane, the preparation of polyurethane composite material comprising (i) crushing raw materials into a 300 mesh powder, dispersing in pure water, ultrasonicating for 1 hour, microwave irradiating for 1 hour, stopping ultrasonic and microwave irradiation, washing, discharging and drying to obtain preprocessing polyurethane, (ii) dispersing the graphene/titanium dioxide cleaning material in pure water and ultrasonicating with stirring to obtain first dispersion liquid, then dispersing multi-walled carbon nanotube/nano-silver antimicrobial material in pure water and ultrasonicating with stirring to obtain second dispersion liquid, heating, dissolving one-fifth pretreated polyurethane in organic solvent to obtain polyurethane solution, dividing into three parts: the first part, the second part, third part polyurethane solution, allowing to stand, mixing first polyurethane solution by ultrasonicating at high-speed, dropwise adding first dispersion liquid, agitating for 30-60 minutes by ultrasonicating, continuing to drop the second polyurethane solution, agitating for 30-60 minutes by ultrasonicating, then dropwise adding second dispersion liquid, and ultrasonicating with stirring for 30-60 minutes, dropwise adding third polyurethane solution and stirring the mixture for 30-60 minutes by ultrasonicating, then dropwise adding graphene quantum dots solution, and stirring the mixture for 30-60 minutes to obtain polyurethane mixture liquid, passing the polyurethane mixture into storage tank of spray dryer, spraying the polyurethane mixture at speed of 200-300 ml/minutes into a spray dryer, and drying to obtain first PU masterbatch, (iii) dispersing the porous graphene in pure water and ultrasonicating with stirring to obtain porous graphite graphene dispersion, heating, dissolving one-fifth of pretreated polyurethane in organic solvent to obtain polyurethane solution, under constant temperature condition, ultrasonicating polyurethane solution with stirring at high speed, dropwise adding porous graphene dispersion liquid, stirring for 30-60 minutes to obtain graphene-polyurethane mixture liquid, passing the graphene-polyurethane mixture into a storage tank of spray dryer, spraying mixture of graphene and polyurethane in a spray drier at speed of 200-300 ml/minutes and drying to obtain second PU masterbatch, and (iv) adding remaining pretreated polyurethane, first PU masterbatch, second PU masterbatch, light stabilizer, coupling agent, leveling agent, dispersion lubricant and antioxidant and melt mixing and then adding into mechanical grinding and pulverizing machine, pulverizing to obtain polyurethane composite powder having average particle size of 30-40 m, drying at 95 degrees C for 2 hours, adding the dried powder into a twin-screw extruder, and then cooling to obtain molding wire, and winding to obtain polyurethane composite material.