S-Triazine Ring-Modified Waterborne Alkyd: Synthesis, Characterization, Antibacterial, and Electrochemical Corrosion Studies

Abstract

The surface coating industry is globally involved in developing useful, eco-friendly, and VOC (volatile organic compounds)-free coating systems, which exhibit promising physico-mechanical and corrosion protective performance. Herein, we report the synthesis of butylated melamine formaldehyde (BMF)-modified soy alkyd (SA-BMF). The structural elucidation and molecular weight of soy alkyd (SA) and SA-BMF resin was carried out by FT-IR, 1H NMR, and 13C NMR spectroscopy and gel permeation chromatography (GPC) techniques. The physico-chemical and physico-mechanical properties were tested by standard protocols. Initial decomposition temperature was measured by thermogravimetric analysis (TGA). The curing study and glass transition temperature were assessed by differential scanning calorimetry (DSC). Hydrophobicity of the coatings was measured in terms of contact angle. The anticorrosion performance of SA-BMF was studied experimentally using polarization techniques and electrochemical impedance spectroscopy (EIS), while the antimicrobial efficacy of the same were tested against Gram positive bacterium Staphylococcus aureus (S. aureus) and Gram negative bacterium Escherichia coli (E. coli) by the agar diffusion method. Overall, our studies revealed that the waterborne SA-BMF coating exhibited higher scratch resistance, impact resistance (150 lb/in.), and bend tests (flexibility retentive 1/8 in.), along with good antibacterial activity and anticorrosive performance. These coatings also find safe usage up to 200 °C.