Self‐healing and in situ real‐time damage detection of stress‐responsive core‐shell microcapsules polymer composites

Abstract Self‐healing technology based on micro/nano‐encapsulated materials has shown great potential in extending material lifespan, preventing performance degradation, and reducing maintenance costs. In this study, a novel mechanically responsive microcapsule is successfully prepared by in‐situ polymerization, which can be used for self‐healing of polymer composites. The core‐shell microstructure is characterized, and its stability and potential self‐healing ability is verified. The microcapsule is introduced into polymer matrix, and the epoxy fingerprint region at the preseted defect location is monitored in real‐time under stress stimulus using infrared spectroscopy, revealing the process from microcapsules rupture to liquid core materials releasing and self‐healing mechanism. Tensile tests are conducted to explore the effect of microcapsule fillers on the mechanical properties of polymer composites. The optimal microcapsule content is determined based on the comprehensive evaluations of self‐healing performance. The core‐shell microcapsules provide excellent in‐situ real‐time self‐healing capability for composite matrix damage during load‐bearing. The self‐healing under stress stimulus can better guarantee the reliability of polymer composites in service. Highlights A novel stress responsive microcapsule is prepared for polymer self‐healing. Stability and self‐healing ability of core‐shell microcapsule is verified. Preseted defect is in situ real‐time detected to reveal self‐healing mechanism. Effect of microcapsule content on composite mechanical properties is explored. Self‐healing better guarantee the reliability of polymer composites in service.