Epoxidized soybean oil-based waterborne polyurethane coatings modified by PEG and gemini quaternary ammonium salt for antifouling applications

In order to alleviate the depletion of petrochemical resources and the resulting environmental pollution problems, it is becoming more and more important to find bio-based polymer materials that can partially or completely replace petrochemical resources. In this study, an epoxidized soybean oil-based antifouling polyols (ESO-PEG) coupled with brush-like anti-fouling polyethylene glycol on the side chain was prepared by epoxy ring opening reaction between epoxy soybean oil and polyethylene glycol monomethyl ether. Secondly, a kind of gemini quaternary ammonium salt antibacterial monomer containing a hydroxyl group (OHGQAS) was synthesized. A series of bio-based waterborne polyurethane coatings with both antifouling and antibacterial activities were synthesized by introducing prepared ESO-PEG and OHGQAS. Antibacterial and antifouling chains suspended on polyurethane side or end chains with good mobility. The effects of ESO-PEG and OHGQAS monomer on the particle size of waterborne polyurethane emulsion, bulk and surface structure, antibacterial and anti-fouling properties of waterborne polyurethane coatings were discussed. The results showed that the introduction of ESO-PEG improved the antifouling performance of polyurethane coatings (antibacterial ratio 96.68 %). In addition, after the introduction of OHGQAS into the structure of waterborne polyurethane, the antibacterial effect of the coating was further improved, that the antibacterial ratio of polyurethane coating with OHGQAS was as high as 99.99 %. These epoxy soybean oil-based waterborne polyurethane coatings hold great promise for antibacterial and antifouling applications. This study develops eco-friendly waterborne polyurethanes from renewable epoxidized soybean oil and quaternary ammonium salts, advancing sustainable materials and green engineering solutions. • A hydroxyl-functionalized gemini quaternary ammonium salt (OHGQAS) was prepared. • Bio-based waterborne polyurethane combining antifouling and antibacterial functionalities were developed. • Coatings containing OHGQAS achieved superior antibacterial performance.