Peelable Antifouling Coating Based on Slow-Curing Polyurea

Abstract

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.