A type of shape memory material based on ethylene-propylene-diene rubber (EPDM)/ polypropylene (PP) thermoplastic vulcanizates compatibilized by magnesium maleate

The effects of magnesium maleate (MgMA) and maleic anhydride (MAH) on the interfacial interaction and the shape memory properties of ethylene propylene diene monomer (EPDM) and polypropylene (PP) thermoplastic vulcanizate (TPV) with sea island structure prepared by dynamic vulcanization were investigated in this study. PP matrix could maintain the temporary shape of TPVs and the crosslinked EPDM phase supplied stress to drive the deformed shape recovery during the shape memory process. MgMA and MAH grafted on PP and EPDM chains verified by FTIR, DMA and SEM, which improved the interfacial compatibility of EPDM and PP and enhanced the efficiency of stress transfer in the shape memory process. The shape fixity ratio (R f ) and shape recovery ratio (R r ) of TPVs compatibilized by MgMA and MAH were almost above 80%. The shape memory property and the mechanical performance of TPVs were all improved compared to that of the sample without compatibilization .