Synthesis and performance of bio-based unsaturated oligomer and containing gum arabic as a novel protective steel coating under UV irradiation

Abstract

The purpose of this study is to prepare UV curable coating based on the reaction of environmental friendly epoxidized olive oil (EOO) with 4-pentenoic acid (PA) to create unsaturated EOO-PA oligomer. The prepared oligomer was confirmed and characterized by FT-IR spectroscopy, viscosity, acid value, and epoxy oxygen content measurements. After that, different thin coating films of prepared oligomer based formulations were applied onto different substrates and subjected to different doses of UV irradiation. All UV cured films of formulations were evaluated in terms of gel content, swelling degree, hardness, bending, gloss, adhesion, scratch, and acid/alkali tests to select the best and high performance formula. Then eco-friendly natural material such as gum Arabic (GA) was evaluated as anticorrosive material for mild steel in 3.5 % sodium chloride by including different concentrations of it to the best prepared formula. The anticorrosion properties of all UV cured coated films containing gum Arabic solution (GAS) were estimated through different tests such as degrees of rusting, blistering, adhesion failure at the scribe, water uptake, and weight loss measurements. Besides, the mechanical, physical, and chemical properties of cured coated panels were examined as well. The results showed that the cured coating films, which contained 7 % of GAS per 100 g coating, could protect the mild steel substrate from corrosion without any significant change in the different properties of cured films.