Bio-based polybenzoxazines coatings for efficient marine antifouling

It is a subject of great practical significance and challenge to endow marine coatings with both excellent bacterial killing and antifouling properties. In this work, a series of bio-based organic coatings demonstrating high antibacterial rate, strong algae-killing ability and satisfied real-sea fouling resistance were reported. The main-chain type benzoxazine (MCBZ) resins were prepared from the renewable daidzein and furfurylamine, together with polyetheramine, long aliphatic chain primary amines, and paraformaldehyde. By adjusting the amines, the overall performance of synthesized MCBZs could be manipulated. Results indicated that the low surface energy of obtained MCBZ could prevent fouling adhesion, and the synergistic effect of long alkyl chains and daidzein led to the efficient anti-fouling. Notably, besides the low curing temperature of 200 °C, excellent processing property and good substrate adhesion (5.02 MPa), poly (12-fu-MCBZ) also possessed 94.5 % antibacterial rate, 100 % algae-killing ability and excellent real-sea antifouling performance. This work provides us a new strategy to solve the marine biological pollution using renewable raw materials.