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

Abstract

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 δ decreased continuously with increasing frequency. The addition of SBS in the TPVs led to enhanced hysteresis behavior and relatively high tan δ.

Keywords:

• compatibilize
• dynamic mechanical properties
• polystyrene
• styrene-butadiene rubber
• styrene-butadiene-styrene copolymer
• thermoplastic vulcanizates

Acknowledgments

The work was funded in part by the Doctoral Fund of Qingdao University of Science & Technology and the Key Laboratory of Rubber-Plastics, Ministry of Education, People's Republic of China.