Alleviation of Iron Corrosion in Chloride Solution by N,N′-bis[2-Methoxynaphthylidene]amino]oxamide as a Corrosion Inhibitor

Abstract

The alleviation of iron corrosion in 3.5% NaCl sodium chloride solution using N,N′-bis[2-methoxynaphthylidene]amino]oxamide (MAO) as a corrosion inhibitor has been reported. The work was achieved using various investigation techniques. Potentiodynamic cyclic polarization (PCP) displayed a powerful inhibition for the corrosion via reducing the iron’s cathodic and anodic reactions. This was reflected in reduced corrosion currents and increased polarization resistances in the presence and upon the increase of MAO concentration. The electrochemical impedance spectroscopy results indicated that MAO molecules provoke the corrosion resistance via increasing polarization resistance. The power of MAO on decreasing pitting attack was also investigated through measuring the change of current with time at −0.475 V(Ag/AgCl). Scanning electron microscopy images were taken of the surface after the current–time measurements were performed in the absence and presence of MAO. The current-time experiments indicated that MAO highly mitigates the corrosion of iron. The energy dispersive X-ray analyzer reported the products found on the tested surfaces. The effect of extending the exposure time from 1 h to 48 h was also tested and was found to alleviate the corrosion of iron, whether MAO molecules are absent or present.