▎ 摘　　要

NOVELTY - Polyurethane material-based modified alumina filler comprises 30-50 pts. wt. polyurethane prepolymer, 10-40 pts. wt. filler, 3-5 pts. wt. curing agent and 5-15 pts. wt. plasticizer. The filler is graphene modified nano alumina, and is prepared by (i) ultrasonically dispersing graphene in mixed solution of sulfuric acid and nitric acid, and then refluxing at 80 degrees C for 4 hours, drying and grinding, (ii) adding pretreated graphene into ethanol for ultrasonic dispersion, adding nano alumina, stirring quickly at 25-35 degrees C to make it fully react, centrifuging, washing with absolute ethanol for multiple times, vacuum drying, and grinding to obtain graphene modified nano alumina. USE - Used as polyurethane material-based modified alumina filler. ADVANTAGE - The polyurethane material has simple process steps, high temperature resistance and excellent tensile strength, and is suitable for casting operations. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for preparing polyurethane material-based modified alumina filler, comprising weighing polyurethane prepolymer, filler and plasticizer and stirring evenly, adding curing agent and stirring evenly, then carrying out vulcanization molding and pouring, and demolding to obtain polyurethane material.