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

Thermoplastic vulcanizates (TPVs) based on styrene-butadiene rubber (SBR)/ethylene-vinyl acetate copolymer (EVA)/high-impact polystyrene (HIPS) blends were prepared by dynamic vulcanization, and the TPVs was compatibilized by styrene-butadiene-styrene block copolymer (SBS). The effects of SBS compatibilizer on mechanical, dynamic mechanical, and morphological properties of the TPVs were investigated systemically. Experimental results indicate that SBS had a good compatibilization effect on the SBR/EVA/HIPS TPVs. The tensile strength went through a maximum value at a compatibilizer resin content of 6 phr, and the elongation at break and tear strength increased with increasing SBS content. Morphology study shows that the vulcanized SBR particles were dispersed in the HIPS matrices. A rubber process analyzer reveals that the elastic modulus increased with increasing frequency and the incorporation of EVA in the TPVs led to the obvious decrease of elastic modulus; however, the further addition of compatibilizer SBS affected the elastic modulus less. The tan delta decreased continuously with increasing frequency. The addition of SBS in the TPVs led to enhanced hysteresis behavior and relatively high tan delta.