Abstract: Three-layer core-shell rubber particles (PSBMs) were prepared via emulsion polymerization. The PSBMs were designed with a hard inner polystyrene (PS) core, an interim soft poly(butadiene) (PB) layer, and a hard external poly(methyl methacrylate)(PMMA) layer, with mass ratios of 23/57/20, 13/67/20 and 0/80/20. PSBMs were introduced into PVC and the effects of morphology and distribution of PSBM on mechanical, optical properties, and deformation mechanism of the blends were studied. It was found that PSBMs dispersed finely in PVC. When the PS/PB/PMMA was 13/67/20, PSBMs toughened the PVC matrix effectively and retained high yield strength and transmittance. It also discovered that the interface between the inner core and interim layer could promote the cavitation of the rubber particles. The cavitation of rubber particles and shearing yielding of the matrix were the toughening mechanisms.

Key words: polybutadiene, poly(methyl methacrylate), poly(vinyl chloride), core-shell structure, rubber particle, toughening, polystyrene