A Hierarchical Energy Dissipation Supramolecular Elastomer with Superhigh Toughness and Cohesive Strength for Adhesive Applications

Modern adhesive applications under dynamic loading conditions demand materials that combine exceptional toughness with high cohesive strength, a combination fundamentally challenging for conventional adhesives. To address this challenge, we developed a supramolecular elastomer adhesive (PU-X) featuring a gradient dynamic bond network comprising single/double hydrogen bonds and Mn 2+ coordination bonds. This innovative architecture enables sequential bond dissociation under stress, where weaker bonds rupture preferentially to dissipate energy, while stronger bonds maintain structural integrity. The optimized PU-X exhibits remarkable mechanical properties, including a tensile strength of 42.7 MPa and a toughness of 166 MJ/m 3, capable of supporting loads exceeding 20,000 times its own weight while demonstrating 246% greater cohesive strength than control samples. The adhesive shows superior bonding performance across various metal substrates, achieving 7.24 MPa lap shear strength and 12.45 MPa adhesion force on iron substrates, which outperform most reported polyurethane adhesives. Furthermore, the optimized PU-X maintains over 88% of its original adhesive strength after six reuse cycles and demonstrates a 91% self-healing efficiency at 40 °C with solvent assistance. This bioinspired design strategy offers a recyclable, high-strength adhesive solution for flexible electronics and wearable devices, paving the way for sustainable materials in demanding applications.