To improve the mechanical properties of poly(vinyl chloride) (PVC), the characters of combining PVC with elastomers were considered. Polybutadiene grafted poly(methyl methacrylate) (PB-g-PMMA, MB) core-shell particles were prepared by emulsion polymerization, and were used as an impact modifier for PVC. The impact resistance, fracture, brittle-ductile transition and the morphology of PVC/MB blends were investigated. It was found that MB particles had a high toughening efficiency for PVC resin, the impact strength was more than 1100 J·m-1 when MB was 8 phr. Two factors influence the impact strength and brittle-ductile transition, one is the modifier content, and the other is core-shell weight ratio. The impact curves are Ω-like shape, the impact strength value is the highest at the middle part and the PVC/MB blends show ductile break behaviors. The core shell ratio of ductile areas are limited from 80/20 to 90/10 for PVC/MB=100/8, and 70/30 to 93/7 for PVC/MB=100/10.

Keywords: polymer composite; toughened; brittle-ductile transition; core-shell particles