A healable polyurethane elastomer with high mechanical strength and record-high toughness enabled by synergistic action of hydrogen bond and Eu3+−phen coordination bonds

Abstract

High-performance elastomers have attracted considerable scientific attention owing to their ubiquitous applications across industrial sectors and daily life scenarios. Despite their technological prevalence, the development of multifunctional elastomeric systems that simultaneously demonstrate exceptional mechanical robustness, remarkable self-healing capability, and intrinsic photoluminescent characteristics remains a critical challenge in advanced materials engineering. In this work, a photoluminescent self-healing polyurethane elastomer with synergistically enhanced network architecture was fabricated through strategic integration of hydrogen-bonded functional motifs and lanthanide (Ln³⁺) coordination complexes featuring dynamic metal–ligand coordination bonds. Consequently, the elastomer achieves exceptional mechanical performance, a high strength of 64.04 MPa, an elongation at break of 2159.18% and an ultrahigh toughness of 512.32 MJ/m³, which is 3.2 times the toughness of typical spider silk (∼160 MJ/m³), even surpasses the toughest spider silk found to date (∼354 MJ/m³). These exceptional mechanical characteristics are principally attributed to the synergistic interplay between rationally architected Eu³⁺-ligand coordination clusters and hierarchically structured hydrogen-bonding domains comprising multifunctional acylsemicarbazide/urethane motifs. The hierarchical hydrogen-bond arrays and Ln³⁺-ligand coordination bonds function as dynamic and firm crosslinks, operating through reversible breakage–reformation cycles to dissipate mechanical energy. This network design simultaneously confers high strength, autonomous self-healing, and recyclability.