Photoinitiated Thiol–Ene Click Reaction for Preparation of Highly Adhesive and Mechanically Stable Silicone Coatings for Marine Antifouling and Anticorrosion

Marine biofouling and corrosion have become the main problems affecting the development of the marine industry. Silicone-based coatings have been widely used for antifouling and anticorrosion due to their low surface energy. However, the poor adhesion and low mechanical stability of these materials limit their application in complex marine environments. In this work, we presented a marine antifouling and anticorrosion coating named POSS-DMA@PDMS-TCM through photoinitiated thiol–ene click reaction combined with (mercaptopropyl) methylsiloxane dimethylsiloxane (PDMS-SH), dopamine methacrylamide (DMA), sulfhydryl-functionalized organosiloxanes (POSS-(SH)₈), and N-(2,4,6-trichlorophenyl) maleimide (TCM). The POSS-DMA@PDMS-TCM coating exhibited strong stability and bonding ability both in air (2.17 MPa) and underwater (2.11 MPa) when the DMA content was 3 wt %. The high antibacterial (98.1% for Staphylococcus aureus and 99.5% for Escherichia coli) and antidiatom (94.5%) properties of the POSS-DMA@PDMS-TCM coatings have also been confirmed. Moreover, the POSS-DMA@PDMS-TCM coatings show excellent antifouling abilities in 120-day marine field tests, reducing fouling by 65.5% in comparison to the blank group. The coating also displayed superior anticorrosion performance with E_corr values of −0.055 V, I_corr values of 7.67 × 10^–6 , and R_p values of 3.10 × 10⁵ Ω for Cu, which benefited from excellent chelating effect and liquid repellency. This study provides a novel strategy for the development of high-quality marine antifouling and anticorrosion coatings.