Preparation of IPDI / GO / PVA / HMMM Microcapsules via In Situ Pickering Emulsion Polymerization for Enhanced Self‐Healing Anticorrosive Epoxy Coatings

ABSTRACT Self‐healing microcapsules were synthesized via an in situ Pickering emulsion polymerization method to address the persistent issue of microcapsule agglomeration and the mechanical compromise associated with high filler loadings in anticorrosive coatings. The resulting IPDI/GO/PVA/HMMM microcapsules exhibited a uniform spherical morphology with a particle size distribution and an encapsulation efficiency of 65.08%. The IPDI core was encapsulated completely by GO/PVA/HMMM shell, elevating the core evaporation temperature from 90°C to 217°C. The microcapsules were then incorporated into epoxy coatings at various contents and evaluated for corrosion resistance. An optimal self‐healing response was achieved at a remarkably low content of 5 wt%, which delivered a low‐frequency impedance modulus (| Z | f = 0.01Hz ) of 3.7 × 10 8 Ω cm 2 after a 168 h immersion test and effectively mitigated corrosion propagation at scribed defects over 720 h salt spray exposure. Scanning electron microscopy further verified the robust crack sealing within 24 h. These findings demonstrate that the incorporation of an appropriate amount of IPDI/GO/PVA/HMMM microcapsules significantly enhances the anticorrosive performance of the coating, thereby providing a valuable reference for future investigations in self‐healing protective coatings.