Double-crosslinked network design for self-healing, highly stretchable and resilient polymer hydrogels

Abstract

Hydrophobic stearyl methacrylate (C18) was captured into sodium dodecyl sulfate (SDS) micelles and self-assembled nanoparticles of an amphiphilic polyurethane macromonomer PU–HEMA were prepared, and they were used as a physical crosslinker and a multifunctional covalent crosslinker, respectively. A reaction system containing acrylamide (AM), the C18 in the micelles and the self-assembled PU–HEMA nanoparticles was designed for constructing chemically and physically double-crosslinked network (CPDN) hydrogels. The prepared CPDN hydrogels have a tensile elongation at break of at least 1400% and can rapidly and fully recover their original shapes in compression experiments, exhibiting superior stretchability and resilience. In addition, the CPDN hydrogels possess a remarkable self-healing behavior and strong self-healing ability even at ambient temperature without the need for any stimulus or healing agent. The novel strategy developed in this study to construct highly stretchable, resilient and self-healing polymer hydrogels is simple yet extremely versatile, thereby opening up a new avenue for the construction of desired functional CPDN hydrogels with excellent mechanical properties.