Hypoxanthine as an Inhibitor for Mild Steel Corrosion in 0.1 M HCl

Abstract

Hypoxanthine (HYP) has been evaluated as a corrosion inhibitor for mild steel in aerated 0.1 M hydrochloric acid by weight loss, potentiodynamic polarisation and electrochemical impedance spectroscopy techniques at 30 and 60 °C respectively. The results showed that hypoxanthine is a moderate inhibitor in the acidic medium. Potentiodynamic polarisation results revealed hypoxanthine to be a mixed inhibitor. Inhibition efficiency increased with increase in the concentrations of hypoxanthine but decreased with a rise in temperature of 60 °C . The adsorption of the inhibitor on the mild steel surface is found to obey Langmuir adsorption isotherm. From the values of E_a and G°_ads obtained, the mechanism of physical adsorption is proposed for the inhibitive action of hypoxanthine.

Key Words: acid solutions, adsorption, inhibition efficiency, potentiodynamic polarisation