Dynamically Vulcanized Thermoplastic Elastomer of Polylactic Acid (PLA ) and Chloroprene Rubber (CR ) Bioblends: Thermoactive Shape Memory Properties
Helen abdollahifar, Hamid Garmabi, Ali Asghar Katbab ABSTRACT
Novel shape memory thermoplastic vulcanizates (TPVs) based on polylactic acid (PLA) and chloroprene rubber (CR) have been fabricated via a dicumyl peroxide (DCP)‐induced dynamic vulcanization process. In situ, melt reactive compatibilization was achieved by molecular grafting of PLA onto the CR chains. This was evidenced by ATR‐FT‐IR spectroscopy, swelling test, and dynamic mechanical thermal analysis (DMTA) results. Field emission scanning electron microscopy revealed co‐continuous morphology for dynamically vulcanized PLA/CR blends even at a 70/30 phase ratio of PLA/CR compared to the unvulcanized counterpart samples. This novel microstructure surprisingly indicated a network with excellent shape memory performance with shape fixity close to 100% and high shape recovery of ~90% compared to pure PLA. Furthermore, the PLA/CR thermoplastic vulcanizate (TPVs) displayed significantly improved tensile and impact strength in comparison with the unvulcanized PLA/CR blends, which are attributed to both the microstructure of the blend and the chemically cross‐linked nature of PLA and CR chains. The DMTA results illustrated higher elastic modulus for TPVs as a result of dynamic vulcanization and their unique microstructure.