Durable and Hydrophobic Self-Healing Coating with Rapid Thermal Activation and Prolonged Corrosion Resistance

Epoxy resin coatings are widely used for corrosion protection of marine aluminum alloy equipment, but they suffer from high water absorption, brittleness, and slow repair, limiting long-term use. To address these issues, we developed an innovative self-healing coating using epoxy resin, nano-silica, a silane coupling agent, furanamine (FA), and bismaleimide (BMI). Our optimally formulated coating exhibited hydrophobicity (97°), high hardness (7 H), strong adhesion (5B), and rapid self-healing within 10 min at 80 °C, a much simpler process than previously reported. Remarkably, the coating maintained excellent self-healing and stable performance after 40 cycles of scratching and heating. Electrochemical tests and equivalent circuit fitting analysis showed superior corrosion resistance before and after scratching and healing, achieving a corrosion protection rate of 99.997%. After 300-day immersion, the coating reduced the corrosion area by 99.84% compared to pure epoxy resin, which had delaminated. This work provides a practical solution for enhancing the durability and anti-corrosion performance of epoxy coatings in marine applications.