Room-temperature self-healing supramolecular polyurethanes based on the synergistic strengthening of biomimetic hierarchical hydrogen-bonding interactions and coordination bonds

Developing a new generation of polymeric materials that integrate robust mechanical properties with ultra-high self-healing efficiency at ambient temperature remains a formidable challenge due to the proverbial trade-offs among strength, toughness, and self-healing ability. Herein, inspired by biological systems (titin protein molecular structure and Nereis jaws), a series of updated supramolecular polyurethanes have been successfully synthesized by incorporating hierarchical hydrogen-bonding motifs into the polymer matrix and subsequently coordinated with Zn2+ ions. Relying on collaborative reinforcement of optimized hierarchical hydrogen bonds and metal-ligand coordination bonds, the resulted supramolecular elastomers exhibited a robust strength of ∼14.15 MPa, an excellent toughness of ∼47.57 MJ m−3, and Young’s modulus of ∼146.92 MPa. Benefiting from the rational design of hard domains, high mobility of chains, and the synergistic effect of multiple non-covalent interactions, the mechanical properties are far superior to the previously reported room‐temperature self‐healing materials. In addition, with the structural design of “inner soft and external hard” model, we also fabricated a bilayer polymer film with a gradient distribution that can achieve rapid self-healing, with an unexpectedly high self-healing efficiency of 95% at ambient temperature in 24 h. This work opens up a new avenue for fabricating room-temperature self-healing materials with robust mechanical strength and toughness at the same time.