A Study of the Electrochemical Behavior of Copper in Acid Medium in Presence of Some Organic Amine Compounds

The rate of corrosion of copper metal in presence of methyl amine, dimethyl amine, diethyl amine, triethyl amine, diethanol amine, and triethanol amine determined by measuring the anodic limiting current. The factors used are type of organic amine compounds and its concentration, concentration of H₃Po₄, viscosity of solution, density, diffusion coefficient, and rate of rotation. It has been found that, the rate of corrosion decrease in presence of these compounds. The inhibition percentage ranged from 9.72% to 80.14% depending on the type of inhibitor and its concentration. It is suggested that the decrease in the rate of corrosion is attributed to the increase in interfacial viscosity of the solution and decrease the diffusion coefficient of the copper ion. It has been found that we can apply the Langmuir, Flory-Huggins, and kinetic adsorption isotherms. It has been found that the rate of inhibition is increases in order: methyl amine, dimethyl amine, diethyl amine, triethyl amine, diethanol amine, and triethanol amine. The rate of corrosion depends on the H₃Po₄ concentration as well as on the electrode height. The limiting current in undivided cells is higher than in divided cells due to the uprising H₂ bubbles, which enhances the rate of corrosion. Also, the rate of corrosion was found to increase by increasing the speed of rotating electrode. The dimensionless groups were calculated, and the relation between them was given and the equation given as following: Sh = 0.5046 Re^0.7201(Sc)^0.33 for methyl amine; Sh = 0.5381 Re^0.7157(Sc)^0.33 for dimethyl amine; Sh = 0.4887 Re^0.7356(Sc)^0.33 for diethyl amine; Sh = 0.5167 Re^0.7207(Sc)^0.33 for triethyl amine; Sh = 0.5373 Re^0.7238(Sc)^0.33 for diethanol amine; and Sh = 0.4958 Re^0.7280(Sc)^0.33 for triethanol amine.