Anti-Permeability Formation Process of Epoxy Coatings Under Simulated Shallow Seawater

The formation of anti-permeability is a critical step in the in-situ repair of organic anti-corrosion coatings under seawater, yet it is significantly influenced by the surrounding marine environment, particularly seawater temperature and applied cathodic polarization potential. In this study, we systematically investigated the effects of temperature and cathodic polarization potential on the permeability of curing epoxy coatings in simulated shallow seawater. Our results demonstrate that the anti-permeability formation process is governed by the competition between seawater penetration and coating curing. At lower temperatures, the EIS-derived evolution of coating resistance suggested heterogeneous electrolyte uptake across the coating surface, whereas at elevated temperatures, the electrochemical response indicated a more uniform progression of ionic ingress. Moreover, enhanced cathodic polarization accelerated both seawater penetration and the curing reaction of the epoxy coating. The underlying mechanisms of temperature- and polarization-dependent permeability formation were discussed in detail, providing theoretical insights into the top-down permeation process during underwater curing, which may inform the development of more effective in situ repair strategies for organic coatings.