Poly(thiol-aldehyde) cation supramolecular toughening effect enables the elastomer to withstand extreme mechanical loads.

For elastomer materials, there is a big challenge to meet a variety of applications with extreme mechanical loading environments, at the same time taking into account recyclability and degradability. This study develops an elastomer (EPUAT) by incorporating quaternary ammonium salts and Poly(Thiol-Aldehyde) with catechol-rich side chains into polyurethane networks. The synergistic interplay of multiple non-covalent interactions, including cation-π interactions and hydrogen bonds. They can significantly enhance the material's cohesion while suppressing polycaprolactone (PCL) chain crystallization. The resulting EPUAT elastomer achieves a remarkable ultimate true tensile strength of 1.02 GPa upon tensile testing, rivaling the mechanical robustness of natural spider silk. EPUAT demonstrates superior impact resistance (159.25 MPa) under high-rate loading, crack tolerance with sustained load-bearing capacity, and outstanding puncture energy of 575.95 mJ. The EPUAT elastomer exhibits favorable damping properties over a broad temperature range, with a tan δ value of 0.75 at −6 °C. The elastomer maintains robust tensile performance even after repeated mechanical cycling, while its dynamic thiourethane bonds facilitate high-efficiency self-healing (demonstrating 93.37 % self-healing efficiency after 48 h at 70 °C) and recycling. These findings establish a pioneering strategy for fabricating next-generation safety and protective materials through biomimetic molecular engineering, offering transformative potential for applications with extreme mechanical loads.