Abstract
The effect of two polyamide compounds on the corrosion behavior of aluminum metal in oxalic acid solution was investigated using potentiostatic and. potentiodynamic anodic polarisation techniques. The inhibition efficiency increases with increasing polyamide concentration until a critical value and. then starts to decrease in high polymer concentrations, indicating a low inhibition efficiency. The inhibitive behavior of these compounds is discussed in terms of adsorption of the polyamide compounds on the metal surface and formation of insoluble complexes. The adsorption process is found to obey Temkin adsorption isotherm. The pitting potential varies with concentration of chloride ions according to a linear relationship. The addition of polyamide compounds shift the pitting potential of aluminum electrode to more positive potentials, indicating an increased resistance to pitting attack.