Non-silicone elastic coating with fouling resistance and fouling release abilities based on degradable hyperbranched polymer

Abstract

Developing eco-friendly antifouling materials for combating marine biofouling has long been a challenging task. Herein, we report a non‑silicone elastomer coating based on hyperbranched poly (ε-caprolactone) (HPCL) cross-linked with an amphiphilic triblock copolymer of poly(ethylene glycol)-block-poly(propylene glycol)-block-poly(ethylene glycol). The polymer coating is prepared by ring-opening polymerization and self-condensation reactions, which can be prepared at a large scale. Such a coating is expected to have a self-renewed surface, fouling resistance and fouling release abilities. Quartz crystal microbalance with dissipation test shows that the coating is degradable, leading to a self-renewed surface. The degradation rate can be regulated by adjusting the HPCL content. Bioassays with bacteria (Staphylococcus aureus and Escherichia coli) and diatom (N. incerta) reveal that the surface with triblock copolymer content of 12.5 wt% or higher can resist the adhesion of microorganisms. The coating also has good fouling release performance with pseudobarnacle removal strength of ∼0.15 MPa, which is comparable with that of silicone elastomer. Marine field test for over 120 days proves the coating is effective in inhibiting marine biofouling due to the synergetic effect of surface renewal, fouling release and fouling resistance. This work provides a facile preparation method for biocide-free antifouling materials.