▎ 摘　　要

NOVELTY - Preparing graphene/polypropylene composite powder material comprises e.g. adding graphite sheet to a mixed solution of concentrated sulfuric acid and nitric acid, stirring, washing the solution repeatedly with deionized water to neutral, drying the solution under vacuum at 100 degrees C to constant weight, and then heating-treating; filtering, washing and vacuum drying; adding surfactant and functionalized graphene into an aqueous ethanol solution; sonicating and vigorously stirring; and subjecting the desired dispersion to rotary evaporation under heating, drying and sieving. USE - The graphene/polypropylene composite powder material is useful for SLS (claimed). ADVANTAGE - The graphene/polypropylene composite powder material has uniform shape, suitable particle size and good liquidity. DETAILED DESCRIPTION - Preparing graphene/polypropylene composite powder material comprises (i) adding graphite sheet to a mixed solution of concentrated sulfuric acid and nitric acid, stirring for 16 hours, washing the solution repeatedly with deionized water to neutral, drying the solution under vacuum at 100 degrees C to constant weight, and then heating-treating at 1050 degrees C for 15 seconds to obtain expanded graphite, placing the expanded graphite in a 70 vol% aqueous ethanol solution, carrying out ultrasonic treatment for 8 hours, filtering and drying in vacuum at 100 degrees C to obtain graphene oxide; (ii) homogeneously dispersing the graphene oxide in an aqueous ethanol solution, carrying out ultrasonic treatment and vigorous stirring, adding silane coupling agent slowly, and maintaining at 70-80 degrees C for 20-28 hours, then filtering, washing and vacuum drying at 60 degrees C to constant weight to obtain functionalized graphene; (iii) adding surfactant and functionalized graphene into an aqueous ethanol solution, sonicating and stirring vigorously to obtain a homogeneous dispersion liquid; (iv) selecting polypropylene powder having a particle size of 10-150 mu m and adding polypropylene powder gradually to the homogeneous dispersion while vigorously stirring, sonicating and vigorously stirring for 24 hours to obtain the desired dispersion liquid; and (v) subjecting the desired dispersion to rotary evaporation under heating, drying and sieving.