Dynamic Tetraoxadiborolane as a Boron–Boron Linkage for an Impact-Resistant, Self-Healing, and Recyclable Elastomer

The boron–oxygen bonds, including boroxine, spiroborate, and dioxaborolane, are a type of representative dynamic bonds and have attracted attention worldwide in scientific and industrial fields. Herein, tetraoxadiborolane, a novel dynamic boronic ester bond derived from the diboron structure, has been studied and introduced into elastomers to achieve exceptional impact resistance with ambient-temperature self-healing and recyclability. Tetraoxadiborolane undergoes spontaneous bond exchange at room temperature, displaying reduced bond energy and accelerated exchange kinetics relative to conventional dioxaborolane. Therefore, the resulting tetraoxadiborolane-based elastomers with boron–boron linkages possess prominent shear-stiffening behavior and excellent energy-dissipation ability, leading to excellent impact resistance (>96% impact force attenuation). Moreover, the dynamic nature of tetraoxadiborolane enables the elastomer with autonomous room-temperature self-healing and recyclability. This work provides a novel tetraoxadiborolane bond to design elastic materials with excellent self-healing and anti-impact performance, which have potential in the application of impact resistance, mechanical durability, and damage recovery.