Thermoplastic vulcanizates based on waste truck tire rubber and copolyester blends reinforced with carbon black

Abstract

Devulcanized rubber (DR) was prepared from waste truck tire rubber via thermo-chemical devulcanization process. Thermoplastic vulcanizates (TPVs) based on blending of DR and copolyester (DR/COPE) were prepared. Effects of carbon black loading on microstructure, mechanical properties and elastomeric behaviors of dynamically cured DR/COPE blends were investigated. It was found that increasing of the carbon black loadings leads to transformation from co-continuous phase structure to dispersion of smaller vulcanized rubber domains in the COPE matrix. Furthermore, the carbon black was well dispersed in the DR/COPE matrix up to 10 wt% and then the aggregates slightly occurred with increasing of carbon black loadings. In addition, dynamic experiments proved that a progressive non-linear behavior was more pronounced with increasing of carbon black loadings. Also, tan δmax of the DR phase decreases with increasing carbon black concentration indicating mainly localization of filler in rubber phase. Moreover, it was found that increases of CB loadings resulted in increase of tensile strength and hardness while the elongation at break was slightly decreased. Additionally, the rate of stress relaxations was found to be increased with increasing CB loadings.