Preparation of fully epoxy resin microcapsules and their application in self‐healing epoxy for the repair of glass fiber composites

Abstract In this work, a novel self‐healing epoxy system has been developed to address the challenge of repairing glass fiber‐reinforced composites, which are widely utilized in aerospace, automotive, marine, and wind turbine applications due to their superior physical and mechanical properties. Damage to these composites can lead to compromised performance and costly repairs. The objective of this study is to offer an efficient repair method that eliminates the need for external interventions. This self‐healing system is created by incorporating microcapsules composed of a solidified epoxy resin shell and a liquid epoxy resin core. The chemical composition of the microcapsule walls is tailored to match the composite substrate, ensuring precise delivery of the repair agent into the damaged regions. The microcapsules are seamlessly integrated into the resin matrix during the fabrication process, with no extraneous components, ensuring compatibility. Rigorous testing, including mechanical and thermal stress assessments, demonstrated that the system successfully initiates self‐repair without affecting the structural integrity of the composite. The results showed that incorporating 15 wt% microcapsules optimized self‐healing and mechanical strength, restoring 90% of flexural strength. The system reduced damage propagation under thermal and mechanical loading, enhancing repair efficiency. This study advances self‐healing materials for aerospace and automotive applications, improving composite durability and reliability. Highlights Novel self‐healing epoxy system developed for composites. Microcapsules deliver repair agents precisely to damage sites. Testing shows effective restoration of mechanical properties. No external interventions are needed for self‐repair functionality. Compatible with glass fiber‐reinforced composite substrates.