3-Aryl substituted triazole derivatives as new and effective corrosion inhibitors for mild steel in hydrochloric acid solution

Abstract

The corrosion inhibition properties of three triazoles derivatives namely 4-amino-5-phenyl-4H-1, 2, 4,-triazole-3-thiol (APTT), 4-amino-5-(2-hydroxy) phenyl-4H-1, 2, 4,-triazole-3-thiol, (AHPTT), 4-amino-5-styryl-4H-1, 2, 4,-triazole-3-thiol, (ASTT) on mild steel corrosion in 1.0 M HCl solution was studied using electrochemical impedance spectroscopy (EIS), potentiodynamic polarization and weight loss methods. Potentiodynamic polarization study clearly revealed that the triazoles derivatives act as mixed type inhibitors. Adsorption of the inhibitors on the mild steel surface followed Langmuir adsorption isotherm. The values of free energy of adsorption (ΔG oads) indicated that adsorption of triazoles derivatives is a spontaneous process and they are adsorbed chemically as well as physically. The values of inhibition efficiency for all triazoles followed the order ASTT > AHPTT > APTT. The Styryl substituted triazole exhibited highest inhibition efficiency 95.2 % at concentration of 5.72x10- 4mol L -1. © 2012 by ESG.