Ultrarobust, Stretchable, and Highly Elastic Supramolecular Elastomer with Hydrogen‐Bond Interactions via sp2 Hybridized Boron‐Urethane Bonds

. The material exhibited excellent fatigue resistance during continuous tensile cycles, while the irreversible deformation disappeared after standing at room temperature. Moreover, the elastomer bespeaks extraordinary elastic restorability, swiftly reverting to its primitive length after being extended to 16 times. This work provides a strategy that the mechanical properties of materials can be enhanced and toughened by utilizing spatial conformational changes in intermolecular interactions.