Zwitterionic–polyurethane coatings for non-specific marine bacterial inhibition: A nontoxic approach for marine application

Abstract

The present work reports synthesis and development of zwitterionic tri-block copolymer-polyurethane (ZTC-PU) coatings which are thermally stable and have hydrophobic properties which can be used for marine applications. The zwitterionic tri-block copolymer (ZTC) (poly(sulfobetaine methacrylate) - polydimethylsiloxane - poly(sulfobetaine methacrylate), polySBMA-block-PDMS-block-polySBMA) was synthesized by ATRP (atom transfer radical polymerization) method. Apart from this, the facile synthesis of silane functionalized acrylic polyol was formulated with 4,4′- Methylene dicyclohexyl diisocyanate (H12 MDI) for the development of polyurethane (PU) coatings. Different weight ratios of ZTC was incorporated in PU to obtain a zwitterionic tri-block copolymer-polyurethane (ZTC-PU) coatings. The ZTC-PU coating exhibit good thermal stability and hydrophobic property. The coating showed excellent non-specific marine bacterial inhibition property along with good stability against gram positive Staphylococcus aureus (S. aureus) and gram negative Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa) microbial strains. This design method reveals the development of zwitterionic-polyurethane coatings with higher amount of zwitterionic moiety in the coating system, that will be efficient and eco-friendly technology for marine bio-fouling application.