Properties and Corrosion Resistance Mechanism of a Self-Healing Octadecyl amine Loaded Ethyl cellulose Microcapsule Coating Loaded with Epoxy Resin

The use of inhibitors in organic coatings is an effective method for protection against corrosion. However, most coatings cannot provide lasting protection to the matrix. In this paper, an intelligent self-healing epoxy coating (EC@ODA/EP) consisting of microcapsules coated with octadecyl amine (ODA) encapsulated by ethyl cellulose (EC) was designed. The corrosion resistance and self-healing properties of EC@ODA/EP were investigated by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The EIS results show that the impedance modulus of EC@ODA/EP is 3.7×10 ⁴ Ω/cm ² at low frequency after 7 days of immersion, which is still higher than that of pure epoxy coating. EC@ODA microcapsules coatings can provide long-term corrosion protection for steel because microcapsules were breaked when damaged, releasing ODA and the multiple synergistic effects of metal matrix and epoxy resin give the coating excellent self-healing ability. The design of self-healing coating system with multiple synergistic effects will provide a new strategy for the preparation of efficient anti-corrosion coating.