PEtOx- b -PDMS- b -PEtOx Block Copolymers as Amphiphilic Additives to Enhance the Low-Fouling Properties of Silicone Coatings

Fouling-release coatings based on silicones are an effective way of protecting surfaces that only allow weak attachment and can be readily cleaned. Conventional polysiloxane materials show moderate antifouling performance, which is commonly enhanced by chemical modification and the addition of biocides and additives. In this work, the synthesis of a set of amphiphilic PEtOx-b-PDMS-b-PEtOx copolymers consisting of a poly(dimethylsiloxane) (PDMS) block and two polyethyoxazoline (PEtOx) blocks and their application as additives in silicone coatings are described. PEtOx blocks were prepared by ring opening polymerization and coupled to amino-terminated PDMS. The hydrophilic additives shift the wettability of the PDMS coating and its propensity to rearrange under water. Using a combination of surface analysis, fluorescence microscopy, and biological assays, the additive solubility, mobility, surface enrichment, and fouling release activity against marine fouling organisms such as Navicula perminuta and Cobetia marina were correlated.