Covalently Cross-Linked Elastomers with Self-Healing and Malleable Abilities Enabled by Boronic Ester Bonds

Covalently cross-linked rubbers are renowned for their high elasticity that play an indispensable role in various applications including tires, seals, and medical implants. Development of self-healing and malleable rubbers is highly desirable as it allows for damage repair and reprocessability to extend the lifetime and alleviate environmental pollution. Herein, we propose a facile approach to prepare permanently cross-linked yet self-healing and recyclable diene-rubber by programming dynamic boronic ester linkages into the network. The network is synthesized through one-pot thermally initiated thiol-ene “click” reaction between a novel dithiol-containing boronic ester cross-linker and commonly used styrene-butadiene rubber without modifying the macromolecular structure. The resulted samples are covalently cross-linked and possess relatively high mechanical strength which can be readily tailored by varying boronic ester content. Owing to the transesterification of boronic ester bonds, the samples can alte...