Some thiazole derivatives as corrosion inhibitors for carbon steel in acidic medium

The effect of some prepared compounds, namely thiazole derivatives on the corrosion of C-steel in 2 M HCl solutions has been studied using the weight loss and electrochemical polarization methods. The results showed that the inhibition efficiency of the investigated compounds was found to depend on the concentration and the nature of the inhibitor. The presence of the substituted donating group (-OCH3) plays an important role in the inhibition percentage of these investigated compounds. The effect of temperature on the corrosion behavior of C-steel in 2 M HCl without and with the inhibitors was studied in the temperature range from 30 to 50°C. The activation and thermodynamic parameters Ea⁎, ΔH⁎ and ΔS⁎ were calculated. The inhibitors were adsorbed on the C-steel surface according to Frumkin's adsorption isotherm. The synergistic effect of some cations (Cu2+, Ni2+, Co2+ and Ca2+) on the corrosion inhibition of C-steel in 2 M HCl in the presence and absence of the investigated compounds was also studied by the weight loss method.