Light-weight and flexible ionomeric blend materials having high self-healing efficiency and exceptional shape-memory effect facilitated by thermoplastic elastomer

Abstract Self-healing and shape-memory proficiencies of polymeric materials have acquired increasing interest. In this study, ionomeric blend materials of two ionomers such as Na- and Zn-neutralized poly (ethylene-co-methacrylic acid) (PEMA) with styrene-isoprene-styrene (SIS) block copolymer (thermoplastic elastomer) were investigated. Such ionomeric blend materials are prepared by the melt-blending technique in different compositions. Fourier-transform infrared spectroscopy (FTIR) confirmed the presence of various coordinated structures in both the ionomers and their respective blends. The blend materials of Na-ionomer exhibited better self-healing behavior than the Zn-ionomer blends. The healing efficiency was increased by increasing healing time as well as SIS content in the blends. The blend sample made up of 80 wt.% Na-ionomer and 20 wt.% of SIS exhibited maximum healing efficiency (~94.0%) as well as significant shape fixity and shape recovery exceeding ~95.0 % in shape fixing and ~99.4 % in shape recovery. The tensile strength of the blend is 12.96 MPa and its elongation is 490.2%. This ionomeric blend material restored its original shape (within 5 sec) as compared to Zn-ionomer/SIS blend (80/20 (wt. %)) blend (within 8 sec). The remarkable self-healing efficiencies and shape memory performances of such light weight and flexible blend may have their various potential applications like aerospace, energy and electronics sectors, soft robotics, and others.