Peelable Antifouling Coating Based on Slow-Curing Polyurea

Marine biofouling on the surface of underwater equipment severely impairs its operation. Conventional antifouling coatings can prevent biofouling; however, the removal of failed or temporary coatings during equipment repair is difficult and may damage the equipment surface. Herein, we report an antifouling coating consisting of polyaspartic ester-based polyurea modified with secondary amine oligosiloxane nanoclusters (NSs) as a crosslinker and a diisocyanate-terminated reactive amphiphilic polymer (RAP). In the resulting slow-curing polyurea coating, the RAP with low-surface-energy fluorinated side chains and polyethylene glycol (PEG) side chains migrates to the coating surface during drying, allowing PEG to inhibit biofouling. The coating demonstrates satisfactory adhesion strength (2-8 MPa) on diverse substrates, including steel, ceramic, copper, glass, and epoxy panels, as well as >90% reduction in fibrinogen adsorption and relative bacterial adhesion values below 10% against S. aureus, E. coli, and P. sp. In addition, the coating exhibits high cohesive strength and moderate interface adhesion. As a result, it can be readily peeled from various surfaces with a peel strength of 1-9 N·cm-1 without damaging the equipment surface. This polyurea coating demonstrates promising application potential as an antibiofouling coating for marine environments.