Inhibiting Effects of Two Derivatives of Amino-Thiophenol on the Corrosion of Copper by Electrochemical Methods

Abstract

Corrosion inhibition of the two thio compounds, 2-{[(2-sulfanyl-phenyl)imino]methyl}phenol (SIMP) and 2-{[(Z)-1-(4-methyl-phenyl)methylidene]amino}-1-benzenthiol (MMAB), as corrosion inhibitors for copper in 15% hydrochloric acid (HCl) have been investigated by potentiodynamic polarization measurements and electrochemical impedance spectroscopy. Potentiodynamic polarization results show that corrosion potentials shift more toward the anodic region in the presence of thio compounds than that of blank solution. The adsorption of inhibitors on the copper surface follows from Langmuir adsorption isotherm. Activation energy (Ea), Gibbs free energy (ΔGads0), enthalpy (ΔH*), and entropy (ΔS*) of corrosion process are calculated by using the experimental measurements.