Bioinspired Silicone-Epoxy Coatings: Combining Cycloaliphatic Resins and Tetrasulfide Bonds for Enhanced Anticorrosion and Antifouling Performance

Abstract

Marine biofouling and seawater corrosion present significant economic challenges to the marine industry. While polymer coatings can effectively delay these processes, traditional coatings often release harmful substances, leading to environmental contamination. Silicone-based fouling release coatings (FRCs) improve antifouling performance by minimizing adhesion with marine organisms, but their low mechanical strength and poor substrate adhesion limit their broader application. This study combines the mechanical properties of cycloaliphatic silicone-epoxy resins with the antimicrobial capabilities of the tetrasulfide (S–S–S–S) bonds in bis(γ-triethoxysilylpropyl)tetrasulfide (Si-69) to address these limitations. Under UV irradiation, cycloaliphatic silicone-epoxy resins form a cross-linked network, ensuring excellent mechanical strength and strong substrate interactions. Simultaneously, Si-69 forms silicon–oxygen–metal (Si–O–M) bonds while maintaining the stability of the S–S–S–S bonds within the coating. The resulting UV-curable coating demonstrated superior antifouling and anticorrosion performance. It achieves a maximum tensile strength of 18.5 MPa, a hardness of 4 H, and strong adhesion to substrates under both dry (3.5 MPa) and wet (3.9 MPa) conditions. The antimicrobial activity of the S–S–S–S bonds enhances the resistance to protein and diatom adhesion. These results demonstrate the potential of this coating for high-performance FRCs in marine environments and its applications in wastewater treatment facilities, heat exchangers, and biomedical devices.