Synthesis method of polyvinyl chloride impact modifier being butadiene, styrene, methyl methacrylate copolymer

The synthesis process of methylmethacrylate, butadiene, styrene copolymer (MBS) includes the synthesis of small size butadiene styrene latex, the size extending including preswelling by adding styrene and methyl methacrylate monomer and size extending by adding aqueous solution of inorganic electrolyte, the two-step graft by adding non-ionic surfactant improving stability of polymerization system. The said process can improve the property of MBS resin and the MBS-PVC copolymer product has high impact strength and transparency.