Dynamically Vulcanized Cis-1,3-Butadiene Rubber/Ethylene-Vinyl Acetate Copolymer/High- Impact Polystyrene Blends Compatibilized by Styrene-Butadiene-Styrene Block Copolymer

Abstract

Compatibilized Cis-1,3-butadiene rubber (BR)/ethylene-vinyl acetate copolymer (EVA)/high-impact polystyrene (HIPS) thermoplastic blend vulcanizates (TPVs) were prepared by dynamic vulcanization, with TPVs being compatibilized by styrene-butadiene-styrene (SBS) block copolymer. The effects of SBS compatibilizer on mechanical, dynamic mechanical, and morphological properties of TPVs were investigated systematically. Experimental results indicated that the dynamically vulcanized BR/HIPS blends did not show an elastomeric behavior when the BR/HIPS blend ratio ranged from 30:70 to 70:30. However, the dynamically vulcanized BR/EVA/HIPS blends compatibilized with SBS showed obvious elastomeric behavior; thus SBS had a good compatibilization effect on BR/EVA/HIPS TPVs. The fractured surface morphology of compatibilized BR/EVA/HIPS TPV was relatively smooth, the interface interaction was strong, and there was no obvious micro-phase separation. BR particles were dispersed evenly in the etched surfaces of BR/EVA/SBS/HIPS TPV. A rubber process analyzer revealed that the storage modulus decreased significantly with increasing strain and the incorporation of compatibilizer SBS in TPVs weakened the Payne effect; the loss modulus showed a pronounced peak and tanδ increased continuously with increasing strain.