▎ 摘　　要

NOVELTY - Preparation of toughening agent involves adding 100-500 parts mass toluene and 5-50 parts mass hyperbranched polyester having terminal carboxyl group into a three-necked reactor, stirring, adding 3-20 parts mass thionyl chloride, reacting, obtaining reaction mixture, cooling the obtained reaction mixture at normal temperature, adding 3-10 parts mass graphene oxide, stirring, adding 0.3-2 parts mass pyridine, stirring uniformly in rate of 200-2000 rpm under protection of nitrogen atmosphere, reacting for 2 hours, distilling to remove excess thionyl chlorides and condensing. USE - Preparation of toughening agent used for plastic composite (claimed). ADVANTAGE - The method provides toughening agent, by a simple process. The plastic composite obtained by the toughening agent has excellent mechanical property, thermal stability and processability. DETAILED DESCRIPTION - Preparation of toughening agent involves adding 100-500 parts mass toluene and 5-50 parts mass hyperbranched polyester having terminal carboxyl group into a three-necked reactor, stirring in rate of 100-1000 rpm under nitrogen atmosphere, slowly dropwise adding 3-20 parts mass thionyl chloride, reacting at 40-95 degrees C for 4-12 hours, obtaining reaction mixture, cooling the obtained reaction mixture at normal temperature, adding 3-10 parts mass graphene oxide, performing ultrasonic stirring for 5 hours under ultrasonic frequency of 300-3000 Hz, adding 0.3-2 parts mass pyridine, stirring uniformly in rate of 200-2000 rpm under protection of nitrogen atmosphere, reacting at 100-150 degrees C for 2 hours, distilling to remove excess thionyl chloride, condensing and obtaining residual yellow semi-transparent liquid as toughening agent. The graphene oxide is prepared using natural flake graphite by Humers method. The hyperbranched polyester having terminal carboxyl group is chosen from 201C hyperbranched polyester having terminal carboxyl group, 202C hyperbranched polyester having terminal carboxyl group, 203C hyperbranched polyester having terminal carboxyl group and 204C hyperbranched polyester having terminal carboxyl group.