Application of the Synthesized Novel 3,6,9,12,15,18,21-heptaoxatricosane-1,23-diyl bis(4-((4-(dimethylamino) benzylidene) amino) benzoate) as a Corrosion Inhibitor for Carbon Steel in Acidic Media

A 3,6,9,12,15,18,21-heptaoxatricosane-1,23-diyl bis(4-((4-(dimethylamino) benzylidene) amino)benzoate) was synthesized and characterized by spectroscopy analysis. The corrosion inhibition effect of the synthesized compound on carbon steel in hydrochloric acid solution had been investigated using potentiodynamic polarization, electrochemical impedance spectroscopy, and weight loss measurements. Polarization studies indicated that the compound acted as a mixed-type inhibitor. Impedance measurement showed that the charge transfer resistance (Rct) increased and double layer capacitance (Cdl) decreased with the increase in the inhibitor's concentration. Adsorption of the inhibitor on the metal surface was found to obey Langmuir isotherm. Quantum chemical parameters were also calculated to characterize adsorption mechanism. Acceptable correlations were obtained between inhibition efficiency and the calculated quantum chemical parameters.