Preparation and characterization of peroxide‐based dynamically vulcanized thermoplastic elastomer of poly (lactic acid)/chloroprene rubber

Abstract

AbstractThermoplastic vulcanizates (TPVs) composed of crosslinked rubber phase with high chemical and thermal resistance have received great attention in pharmaceutical and biological applications. In the present work, attempts have been made to prepare TPVs based on poly (lactic acid) (PLA) and chloroprene rubber (CR) via a melt mixing process in the presence of dicumyl peroxide (DCP) and a combination of magnesium oxide (MgO) and epoxidized soybean oil (ESBO) as hydrochloric acid (HCl) scavenger to minimize CR degradation by DCP. A honeycomb co‐continuous micromorphology was observed for the fabricated TPVs samples through scanning electron microscopy, significantly different from the classical “sea‐island” micromorphology. However, the PLA/CR vulcanizates prepared by only DCP did not show enhanced mechanical properties due to the CR thermal decomposition by the DCP radicals. Therefore, a novel formulation was designed to prevent thermal decomposition of the CR phase during dynamic vulcanization by the incorporation of a combination of ESBO and MgO as efficient HCl scavenger. The stabilized TPV samples exhibited an intense brittle‐ductile transition effect and improved tensile mechanical. The obtained results implied the effectiveness of ESBO and MgO in stabilizing CR phase during peroxide dynamic vulcanization process.