Benzothiazole-modified polyurethane antifouling coatings with in-situ migration: Macedonian phalanx offensive-defensive strategy

The use of traditional antifouling techniques in coatings leads to an increase in “ineffective” antifouling agents. Polyurethane (PU) can be easily customized by adding functional segments or anchoring antifouling agents to enhance its antifouling properties and reduce the “ineffective” content. In this study, inspired by the ancient Macedonian phalanx's efficient combat strategy of combining spears and bucklers, a series of environmental benzothiazole-silicon-contained polyurethane (PBTS) antifouling coatings with in-situ migration property in water was prepared. The content and length of the benzothiazole-modified siloxane functional chain segment were modified to improve its antifouling properties. The PBTS coatings can realize adhesion inhibition ratios up to 88.2 % and 96.3 % for Nitzschia closterium and Halamphora sp., a comprehensive antibacterial ratio of 70 % and good mussel adhesion inhibition capabilities. Importantly, the PBTS10-1 coating showed an outstanding performance in the field test. With this strategy, efficient antifouling “combat” was achieved and a promising environmental PDMS-modified PU with good adhesion strength was suggested.