Self-healing quadruple-shape memory hydrogel based on imine, coordination, and borate bonds with tunable mechanical properties

PAM/OSA/PVA hydrogel was prepared by simple copolymerization using acrylamide (PAM), oxidized sodium alginate (OSA), and poly (vinyl alcohol) as monomers. The hydrogel exhibited a quadruple-shape memory effect based on imine, coordination, and borate bonds. Self-healing properties of the quadruple-shape memory hydrogel were observed to evolve due to the imine and borate bonds. The hydrogel demonstrated tunable mechanical properties because of supramolecular interactions including OSA –Ca 2+ , PVA –borax, and OSA –PAM in different conditions. The new hydrogel is envisaged to increase the variety as well as broaden the design and manufacturing of shape memory hydrogels. Dual multi-shape memory images of PAM/OSA/PVA hydrogel and its shape memory mechanism.