Driving Forces of a Room-Temperature Self-Healing Elastomer for Multiscale Healing

Supramolecular polymers often exhibit self-healing capabilities following mechanical damage. However, the detailed recovery processes and underlying driving forces remain poorly understood. In this study, we developed a room-temperature self-healing elastomer by introducing intermolecular ionic interactions between untangled polymer chains. These interactions enable the material to fully repair macroscopic mechanical damage (e.g., cuts) within 5 h at room temperature without compromising its mechanical properties. We quantitatively characterize the multiscale healing processes, ranging from ionic bond reformation and weak physical network repair to strong physical network recovery and mechanical property restoration. These healing processes are systematically correlated with the multiscale molecular motions and relaxation dynamics of ionic aggregates. Our findings reveal that ionic bond recovery occurs synergistically with segmental motion, facilitating the repair of a weak physical network and driving shape recovery after deformation. Meanwhile, the restoration of the strong network is governed by the complete relaxation of the ionic aggregates. For macroscopic damage, full healing requires an additional contribution of terminal flow.