Mechanically robust, intrinsically self-healing crosslinked polymer enabled by dynamic urea bond exchange reaction

Designing a crosslinked polymer with self-healing, recyclable, and mechanical properties is a significant challenge in the field of self-healing chemistry. Herein, robust, intrinsically self-healing, crosslinked polyureas (C-PUs) are prepared via a facile one-pot photo-induced copolymerization to address the aforementioned limitation. The key strategy involves the introduction of a synthetic monomer with reversible urea bonds into the polymer network as a versatile dynamic crosslinker. The resultant C-PUs are a class of resource-saving materials with a combination of excellent intrinsic self-healing capability with outstanding mechanical robustness. Notably, the properties of the materials can be easily tuned by simply adjusting the dynamic crosslinker content. In addition, an environmentally friendly polymer reprocessing is achieved and the potential of the materials in the smart anticorrosion application is investigated. These desirable properties are attributed to the underlying topological network rearrangement enabled by the dynamic urea bond exchange reaction, which is confirmed by stress relaxation tests. Therefore, the resulting self-healing C-PUs can serve as models to extend the scope of applications in smart protective materials or ocean engineering.