ELECTROCHEMICAL BEHAVIOUR OF COPPER IN SOME AQUEOUS SOLUTIONS

The present work is assigned to study the corrosion of copper in 2M nitric acid solution and the inhibiting effect of some phthalimide and glycine derivatives by the weight loss and galvanostatic polarization techniques.The obtained results showed that the inhibition efficiency of these compounds increased by increasing their concentrations and decreased by raising the temperature, so that the adsorption of these compounds is physically adsorped on the copper surface.Temkin’s adsorption isotherm fits the experimental data for the studied compounds so that some thermodynamic parameters for adsorption of these compounds were calculated.The effect of temperature on the corrosion rate was studied using weight loss method at temperature range 303 – 318 K. The results revealed that by increasing the temperature, the rate of corrosion is increased. Linear Arrhenius plots were obtained in theThe mechanism of the inhibition process was determined using the polarization technique. The measured Tafel slopes indicate that these compounds act as a mixed type inhibitors but cathode is more polarized when an external current was applied.The results were explained on the basis of the molecular structure and the substituent groups and their charge densities.