Inhibition of Acidic Corrosion of Low Carbon Steel by Novel Synthesized Benzothiazole Derivatives

Two novel benzothiazole derivatives (2-[(1,3-benzothiazol-2-ylamino)methyl]-1-naphthol (1) and 2- {[(6- methyl-1,3-benzothiazol-2-yl)amino]methyl}-1-naphthol) (2) have been synthesized. The protecting effect of these compounds on low carbon steel (LCS) in 0.1M hydrochloric acid (HCl) solutions as corrosion media was investigated using potentiodynamic polarization technique, and electrochemical impedance spectroscopy (EIS). The potentiodynamic polarization curves indicate that investigated benzothiazole derivatives were acting as anodic inhibitor. The inhibitive action of inhibitor molecules may be interpreted in view of their adsorption on the LCS surface. The adsorptions of benzothiazole derivatives on metal surface in 0.1M HCl solution were found to obey Temkin adsorption isotherm. Thermodynamic parameters of adsorption (Kads, ΔGads) of investigated inhibitors were calculated using Temkin adsorption isotherm.