Mastering Hydrogen Bonding at Hard–Soft Interfaces for Ultrahigh Damage Resistance in Elastomers

Optimizing supramolecular interactions is crucial for enhancing the damage resistance of elastomers under extreme mechanical stresses. However, the underlying mechanisms remain not fully understood, making targeted design challenging. This study thoroughly investigates a series of polyurethane elastomers and presents a strategy to enhance elastomer damage resistance by tuning the number and strength of hydrogen bonds at the hard–soft interface. Within these elastomers, we find that the hardness is positively correlated with the number and strength of hydrogen bonds, while toughness increases with the number of hydrogen bonds, reaching a maximum at moderate bond strength. Elastomers with both high hardness and toughness demonstrate superior impact resistance, while the best tear resistance is achieved with moderate hardness and high toughness. By balancing hydrogen bond acceptors in the soft segment with donors in the hard segment, an elastomer with an exceptional impact strength of 9.2 MJ m–2 is obtained, and tear resistance of 275.0 kJ m–2 is achieved by modulating the interaction strength. This research clarifies structural factors influencing damage resistance, including the number and strength of hydrogen bonds at the hard–soft interface, offering valuable insights for the design of highly impact- and tear-resistant elastomers.