Corrosion of copper in presence of aromatic acids

The rate of corrosion of copper plates was determined by measuring the limiting current of anodic dissolution of copper in presence of different aromatic acids. It has been found that the aromatic acids increase the rate of corrosion by amount ranging from 1.4 to 41.4 depending on the concentrations of acids and their structures. In case of 4-aminobenzoic acid, the acceleration of electropolishing decreases with increasing the concentration of acids while in case of salicylic acid an inhibition process takes place. It was found that the rate of electropolishing depends on the H3PO4 concentration as well as on the electrode height. Also, the rate of electropolishing was found to increase by increasing the speed of rotating cylinder electrode. The dimensionless groups were calculated and the relations between them are given. The general correlations in presence of acids are Sh = 0.9517 Re-0.571 Sc-0.33 for benzoic acid Sh = 0.3751 Re-0.686 Sc-0.33 for 4-aminobenzoic acid Sh = 0.1958 Re-0.679 Sc-0.33 for phthalic acid Sh = 1.5871 Re-0.533 Sc-0.33 for 4-nitrobenzoic acid Sh = 0.3705 Re-0.714 Sc-0.33 for 2-nitrobenzoic acid Sh = 0.4398 Re-0.667 Sc-0.33 for 4-chlorobenzoic acid Sh = 0.3843 Re-0.689 Sc-0.33 for salicyclic acid.