Dual Microcapsules Self‐Healing Performance in Glass Epoxy Composite Under Flexural Load

ABSTRACT This study examines the impact of dual‐microcapsule reinforcement in glass epoxy composites on self‐healing performance under flexural loading. Epoxy and hardener microcapsules encapsulated in a polymethylmethacrylate (PMMA) shell were synthesized using an oil‐in‐water emulsion solvent evaporation technique. Scanning electronic microscopy (SEM) analysis was conducted to assess the morphology, size variation, and distribution of the microcapsules. Glass epoxy laminate was fabricated using a manual layup technique by incorporating dual microcapsules with 5, 10, and 15 wt%. The effect of dual‐microcapsule reinforcement on flexural strength and healing efficiency was evaluated through three‐point bending tests. These results demonstrated a notable improvement in flexural strength with a maximum increase of approximately 27% observed in composites reinforced with 10 wt% microcapsules compared to the unreinforced composite. Furthermore, all the microcapsule‐reinforced composites exhibited significant healing efficiencies of 42%, 63%, and 50% for 5, 10, and 15 wt% microcapsule‐filled composites, respectively. The SEM analysis of the fractured composites revealed insights into fracture mechanisms, including microcapsule rupture, crack deviation, and the formation of a rough matrix surface, indicating successful polymerization and effective mitigation of microcrack propagation.