Evaluation of Impedance Measurements on Al-Pure Corrosion in 1.0 M HCl in the Presence of Organic Schiff

The inhibition performance of two Schiff bases, namely (A) Benzenamine, 2-chloro-N[( 4-methoxyphenyl)methylene] and (B) Benzenamine, 3-chloro-N-[(4methoxyphenyl) methy-lene] as corrosion inhibitors for Al-Pure in 1.0 M HCl has been investigated by galvanostatic polarization measurement, electrochemical impedance spectroscopy (EIS) and weight loss method. Galvanostatic polarization study showed that two inhibitors are mixed type with predominant action on the cathode. The adsorption of inhibitors on Al-Pure surface was found to follow Langmuir adsorption isotherm and the thermodynamic parameters (Ea, ΔGads and Qads) were determined. Two Schiff bases have shown remarkable inhibition on the corrosion of Al-Pure in 1.0 M HCl solution. The high inhibition efficiency was attributed to the blocking of active sites by adsorption of inhibitor molecules on the metal surface.