Corrosion of Copper in Presence of Acetic Acid Derivatives

The anodic corrosion of copper in presence of acetic acid derivatives were determined by measuring the limiting current. It is found that the rate of corrosion increased by decreasing H₃PO₄ concentration and electrode height. The experimental results showed that the inhibition efficiency increased with increasing concentration of the investigated compounds at a fixed temperature, but decreases with increasing temperature. Values of activation energy indicate that the reaction is diffusion controlled. The isotherm Langmuir, Temkin, and Flory Huggins are applied. The values of free energy of adsorption (ΔG_ads) obtained indicate the spontaneous adsorption of the inhibitor. The overall mass transfer correlations under the present conditions have been obtained using dimensional analysis method. The results agreed with the previous studies of mass transfer to rotating cylinder in turbulent flow.At the end of the corrosion process the morphology of the specimens after experiment is monitored using scanning electron microscope (SEM). SEM examination of the copper surface revealed that these compounds inhibited copper from corrosion by adsorption on its surface to form protective film. The presence of these organic compounds adsorbed on the electrode surface was confirmed by SEM investigations.