Composite coatings based on silicone-modified polyurethane and marine natural product chlorogentisyl alcohol for marine antifouling

Marine biofouling has a serious impact on marine facilities, and traditional antifoulants may cause secondary pollution to the ocean. As chlorogentisyl alcohol (3-chloro-2,5-dihydroxybenzyl alcohol, CHBA) is a marine natural product with excellent antifouling properties, CHBA and its analogues are prepared and combined with silicone-modified polyurethane (SiPU) for development of potential green composite coatings for marine antifouling. Lubricant polydimethylsiloxane and antifoulant CHBA endow the composite material with antifouling properties under dynamic and static conditions, respectively. CHBA is steadily released from the composite coating at a rate of 28 μg/(cm²·d). As one of the CHBA/SiPU composite coatings, SiPU-3 exhibits inspiring activities against Escherichia coli (Gram-negative bacteria), Staphylococcus aureus (Gram-positive bacteria) and Vibrio fischeri (marine bacteria), with all inhibition rates exceeding 90.0 %. This composite coating has high antiprotein adsorption ability and algal inhibition rate, showing desirable antifouling performance for up to 90 d in seawater. This work will provide new possible considerations in the development of marine antifouling coatings using marine natural antifoulants.