The Synthesis and Synergistic Effect of Heterocyclic Groups Grafted on Acrylic Polymers by Ester Groups for Marine Antifouling

Using a synthetic antifoulant is an alternative technique to using a natural antifoulant for its economical and large-scale production characteristics. In this study, we synthesized allyl 3-oxzo[d]isothiazole-2(3H)-carboxylate (BIT-C) and a series of other heterocyclic compounds, including triazole, pyridine, and thiazole derivatives. These heterocyclic monomers were used to prepare a new series of acrylic polymers by grafting them onto the side chains. The weight change on the 42nd day was less than -0.091 mg/cm-2, indicating that antifoulants can be released into seawater consistently and enduringly. The antibacterial and anti-algae tests revealed that all the polymers had exceptional inhibition rates on E. coli, S. aureus, Chlorella, and Chaetoceros curvisetus, with the highest inhibition rates of 99.81%, 99.22%, 92.70%, and 95.42%, respectively. Furthermore, the oyster and barnacle density and algae coverage rate were only about 200 per square meter and 10%, compared to 1800 per square meter and 100% of a blank plate after 90 days hanging in a real marine environment, showing a promising antifouling performance. This work verifies the possibility of a method for grafting different heterocycles on a single polymer to make a series of polymers that can be useful as an environmentally friendly antifouling coating.