Easy-to-process, opaque and high-impact methyl methacrylate-butadiene-styrene polymer for polyvinyl chloride and preparation method thereof

An easy-to-process, opaque and high-impact methyl methacrylate-butadiene-styrene (MBS) polymer for polyvinyl chloride (PVC), having a core-kernel-shell (three-layer) structure, wherein the MBS comprises the following components by mass:

• 1-20% of core, 70-85% of kernel and 5-20% of shell;
• the core is a semi-hard, lightly crosslinked copolymer of a styrene (St) monomer and an acrylate monomer;
• the ratio of the St monomer to the acrylate monomer is 95:5 to 5:95;
• the St monomer comprises St or methylstyrene;
• the acrylate monomer comprises one or more of methyl acrylate, ethyl acrylate, butyl acrylate, and 2-ethylhexyl acrylate;
• the kernel is a soft, lightly crosslinked butadiene (BD)-St polymer with a low glass transition temperature, and the ratio of the BD to the St is 100:0 to 80:20;
• the shell is a copolymer of St, butyl acrylate and methyl methacrylate (MMA) with a high glass transition temperature;
• the St, the butyl acrylate and the MMA account for 0.2-5%, 0.2-2% and 13-20% by mass, respectively.