Self-Recoverable, Energy-Dissipating, and Healable Chain-Extended Supramolecular Polyurethanes and Poly(urethane–urea)s for Impact-Resistant Systems

Materials utilized for impact protection must be capable of effective absorption and dissipation of external impact forces as well as being lightweight, flexible, and comfortable. One strategy to meet these stringent criteria is through the exploitation of adaptive dynamic networks. Herein, we report a series of chain-extended supramolecular polyurethane and poly(urethane-urea) elastomers, which utilize both hydrogen bonding interactions and disulfide units to impart structural stability, reprocessability, and reversible adaptability. The key design element of these phase-separated materials is the use of two distinct dynamic bonding mechanisms within the hard domains, which serve to efficiently reinforce the elastomeric assemblies. The optimum elastomer exhibited excellent self-recoverability (91% and 99%) after relaxing for 30 and 60 s, respectively, at 20% compression. During loading-unloading compression cycles, the elastic recovery ratios of this elastomer reached 77 ± 0.3% with dissipated energies of 235,000 J m^-3 at a deformation of 80%. This study highlights how the combination of noncovalent interactions and dynamic covalent bonding can be utilized to generate elastomers capable of rapid autonomous healing and property recovery while simultaneously providing exceptional energy dissipation, paving the way for the impact-resistant systems.