Comparative Study on the Degradation of Two Self-Polishing Antifouling Coating Systems with Copper-Based Antifouling Agents

The degradation processes of two self-polishing antifouling coatings containing copper-based agents (CuSCN and Cu2O) in 3.5% NaCl solution the protection effect coating systems were studied by electrochemical impedance spectroscopy (EIS), Fourier transform infrared (FTIR) scanning electron microscope (SEM/EDS) methods. results demonstrate that after immersion for 1525 d at room temperature, still have very good property 5083 Al alloy substrate, manifesting high value low-frequency impedance. Alternate low temperature test (45 °C 12 h + 25 h) leads to serious damage topcoat, failure is mainly manifested many micro-pores micro-cracks. Because CuSCN agent particle has bigger diameter slightly higher solubility than Cu2O agent, established dissolved released during hydrolysis process are relatively larger, which more decrease a worse protective system substrate.