Large‐Scale Damage Healing in a Stiff, Self‐Lubricating Epoxy Composite

ABSTRACT Self‐lubricating structural components are prone to suffer severe lubrication failure and wear loss during long‐term service in harsh environments, yet current self‐healing strategies remain confined to micro‐scale defects or require sacrificing material's stiffness to realize effective healing. Here, we reported a rigid dual dynamic bonds network material (DDBs, ∼2.16 GPa in modulus) capable of healing large‐scale damage (∼500 µm in width) without compromising mechanical integrity. The network was constructed by co‐curing commercial epoxy monomer with small‐molecule agents containing dynamic disulfide and ester bonds, enabling rapid topological rearrangement within a stiff polymer matrix. The incorporation of phase‐change paraffin further coupled autonomous lubrication with structural healing. The resulting DDB‐1/5P (DDB‐1+5 wt.% paraffin) exhibited high load‐bearing capacity, stable self‐lubricating, and anti‐wear (wear rate of 1.49 × 10 −6 mm 3 /(N·m)) performance, and it sustained multi‐cycle recovery of both macroscopic morphology and micromechanical properties. In addition, the excellent dynamic feature endowed the material with recyclability, allowing property customization through the incorporation of diverse fillers. This study provides a novel strategy for developing high‐performance self‐lubricating robust materials with large‐scale damage healing capability, which is highly expected for engineering applications.