Electrochemical studies of 1,2,3-Benzotriazole inhibitor for acrylic-based coating in different acidic media systems

In this work, the corrosion inhibition performance of 1,2,3 – Benzotriazole (BTA) as an organic inhibitor for cold rolled mild steel in an acidic medium was investigated. For this, different loading ratios of BTA were utilized and their efficiency as corrosive inhibitor either within the coating film or within the electrolyte was discussed. The first set of the samples was fabricated by the incorporation of 0.1 wt.%, 0.5 wt.%, and 1.0 wt.% BTA within the acrylic polymer host matrix. The influence of BTA to the structural, optical, and adhesion properties of the acrylic coating films was examined. The obtained results revealed no significant changes resulted from the addition of different concentrations of BTA. The other set of the samples was developed by dissolving different concentration of BTA specifically, 100 ppm, 500 ppm, and 1000 ppm within the acidic electrolyte. All tested substrates were coated with acrylic based coating systems in the presence of polyisocyanate (NCO) as a curing agent. 0.5 M H₂SO₄ was used as the corrosive electrolyte and the corrosion protection performance of the two sets of the samples was investigated via electrochemical impedance spectroscopy (EIS). The obtained results confirmed the way of introduction influenced the performance of the BTA as a corrosion inhibitor. The best corrosion protection and the intact behavior was observed by adding 0.1 wt.% of BTA within the acrylic coating film even after 30 days of exposure of coated substrate to H₂SO₄ solution.