Investigation of shape memory and mechanical properties of styrenic thermoplastic elastomer/PCL blends: Effect of blend composition

In this study, heat-responsive shape memory thermoplastic polymer blends were developed using a solution blending technique. The blends consisted of maleic anhydride grafted SEBS (SEBS-g-MA) as the elastomer phase and poly(caprolactone) (PCL) as the switch phase. The investigation focused on understanding the effects of blend composition on morphological and mechanical properties. Blends containing 40 and 50 wt % of PCL (SEBS60 and SEBS50, respectively) exhibited a co-continuous morphology. Increasing the PCL content led to higher Young's modulus and storage modulus at room temperature, while decreasing the creep strain. Shape-memory tests demonstrated promising results, with shape fixing ratios (Rf) reaching up to 98.54% and shape recovery ratios (Rr) up to 84.01%. Notably, the SEBS60 blend displayed the best shape-memory performance, achieving an Rf value of 97.15% and an Rr value of 76.29%. Cyclic shape-memory tests for the same blend maintained Rf values above 96% and Rr values above 82%.