Glassy Hybrid Network with Excellent Toughness and Self-Healing Ability at Ambient Temperature

Abstract

We developed a tough and healable polymeric glass (THG) through tailoring amine-carboxylate salt bridges between a hyperbranched polymer and a high-molecular-weight linear copolymer. The high density of salt bridges leads to high yield strength (up to 43.9 MPa) and Young's modulus (1.1 GPa) of THG. Meanwhile, the large free volume of the hyperbranched polymer and the molecular entanglements of the linear copolymer enable outstanding toughness (up to 86.3 MJ/m3), outperforming most commercial glassy polymers. More interestingly, THG can readily heal mechanical damage at ambient temperature below its glass transition temperature due to the reversible crosslinking and secondary relaxations of the network. Therefore, this approach enables the development of glassy polymers with combination of high strength, excellent toughness and self-healing ability in glassy state.