High-efficiency self-repairing anticorrosion coatings with controlled assembly microcapsules

Based on the principle of emulsion technology and self-assembly of materials, aromatic isocyanate derivatives easily reacted with polyols to form polyurethanes, and nonaromatic isocyanate derivatives were responsible for generating the capsule core of the self-healing microcapsules. In this paper, epoxy resin-based self-healing smart anticorrosion coatings with different types of microcapsules were prepared. The cores were IPDI/TMP–IPDI/DiPE–IPDI. The optimal conditions for the preparation of self-repairing microcapsules to achieve controlled assembly of a microcapsule material structure were determined. We set up a test model, incorporating thermal analysis, depression repair level calculation, salt spray corrosion tests, adhesion tests, and other indicators of application performance. The corrosion resistance was in the order: DiPE–IPDI > TMP–IPDI > IPDI > pure epoxy. The experimental results showed a self-healing efficiency of more than 80% for cores of DiPE–IPDI. Taking into account the overall properties, the best-quality coatings contained approximately 5% microcapsules of DiPE–IPDI.