Thermoplastic elastomers based on high-density polyethylene and waste ground rubber tire composites compatibilized by styrene–butadiene block copolymer

Abstract

Thermoplastic elastomers (TPEs) based on high-density polyethylene (HDPE)/waste ground rubber tire (WGRT) powder composites were prepared by melt compounding, and the composites were compatibilized by styrene–butadiene–styrene block copolymer (SBS). The effects of the SBS compatibilizer on mechanical properties, morphological properties and the Mullins effect of the composites were investigated systemically. Experimental results indicated that SBS had a good compatibilization effect on the HDPE/WGRT composites. Compared with HDPE/WGRT composites, the tensile strength and the elongation at break went through maximum values at a compatibilizer resin content of 12 phr. Morphological study showed that the interface interaction of the HDPE/WGRT composites compatibilized by SBS was strong, which contributed to the significantly improved mechanical properties. The Mullins effect results showed that the softening appeared after the first loading of the HDPE/WGRT and HDPE/SBS/WGRT composites, the maximum stress decreased at the later cycles, and the residual deformations in uniaxial loading–unloading cycles of the HDPE/SBS/WGRT sample were lower than those of the HDPE/WGRT sample, indicating that the elasticity of the HDPE/SBS/WGRT TPE was improved.