Ru(II) Catalyst Enables Dynamic Dual‐Cross‐Linked Elastomers with Near‐Infrared Self‐Healing toward Flexible Electronics

Abstract Perusing elastomers capable of self‐healing offers new opportunities to enable next‐generation flexible electronics, but remains greatly challenging; because, few of them can simultaneously possess desirable mechanical strength, elasticity, and self‐healing efficiency. Herein, a dynamic dual‐cross‐linked networks strategy is employed to develop the elastomers via synthesis of ionic polymer catalyzed using the Grubbs's third‐generation catalyst (G3) and subsequent ureido‐pyrimidinone (UPy) grafting. Specifically, UPy exhibits a unique gradient distribution on ionic polymer chains. Large UPy clusters form in the dense UPy region with robust cross‐links that can stabilize the system, while UPy dimers in sparse regions with weak ionic interactions can act as sacrificial bonds for energy dissipation. Therefore, the obtained elastomers exhibit superb mechanical properties with high stretchability (1900%), high toughness (33.8 MJ m⁻³), and excellent elasticity (>85%). Importantly, deactivated [Ru] = CHOEt complex (G3 derivative) is proved to have an inherently outstanding photothermal effect under near‐infrared (NIR) irradiation. Benefiting from this feature, the elastomers achieve nearly complete self‐healing within 4.5 min under NIR. Furthermore, the elastomers are employed as the base materials to construct flexible self‐healing conductors with stable conductivity even being stretched to 1200%. This work exercises a profound influence on the rational design of high‐performance self‐healing elastomers.