Dynamically vulcanized high impact polystyrene/high vinyl polybutadiene rubber composites compatibilized by styrene–butadiene–styrene block copolymer

Abstract

Thermoplastic vulcanizates (TPVs) based on high impact polystyrene (HIPS)/high vinyl polybutadiene rubber (HVPBR) composites were prepared by dynamic vulcanization, and then compatibilized by styrene–butadiene–styrene (SBS) block copolymer. The effects of SBS compatibilizer on mechanical properties, Mullins effect, morphological and dynamic mechanical properties of the TPVs were investigated systematically. Experimental results indicated that SBS had an excellent compatibilization effect on the dynamically vulcanized HIPS/HVPBR composites. Compared with those of HIPS/HVPBR composite, the tensile strength, elongation at break and tearing strength of HIPS/HVPBR composite with 12 phr SBS incorporation were improved by about 163%, 312% and 67%, respectively. Mullins effect results showed that the compatibilized HIPS/HVPBR TPVs had relatively lower residual deformation and internal friction loss than those of HIPS/HVPBR composites, indicating the improvement of elastic reversibility. Morphology studies showed that the interface interaction of the TPVs was enhanced and the particle sizes of the dispersed phase were decreased with the incorporation of SBS compatibilizer. Dynamic mechanical analysis studies showed that the Tg s of HIPS and HVPBR phases were slightly shifted toward low temperature with the incorporation of SBS, which indicates the significant improvement of the compatibility.