Fast room‐temperature self‐healing vitrimers enabled by accelerated associative exchange kinetics

Abstract

Enhanced dynamicity remains a matter of concern in vitrimer design for fast self-healing materials. In this study, we fabricated pseudo-cyclic vinylogous urethane (VU) vitrimers with accelerated associative exchange kinetics and enhanced mechanical properties based on a bottom-up strategy. Unique cation-templated pseudo-crown ether building blocks were prepared via coordination of alkali metal ions. The resultant pseudo-cyclic VU vitrimers possess higher crosslinking densities and more orderly arranged network topologies than their counterpart vitrimer based on linear building blocks, which were confirmed by swelling experiments and free volume parameters determination. Tensile strength and toughness were significantly improved, which are positively correlated with complexation strength. Furthermore, both stress relaxation and creep recovery experiments demonstrate that pseudo-cyclic vitrimers can undergo more rapidly topological rearrangement due to the synergetic effect of unique pseudo-cyclic structure and alkaline metal salts-promoted catalytic dynamic exchange. Given that the resultant vitrimers exhibit a high-efficient self-healable capability at room temperature. This work contributes to tailor-make fast room‐temperature self‐healing vitrimers via a building block design and expands the potential of vitrimers.