A COMPARATIVE-STUDY OF THE INHIBITION EFFECTS OF BENZOTRIAZOLE AND 6-ANILINE-1,3,5-TRIAZINE-2,4-DITHIOL MONOSODIUM SALT ON THE CORROSION OF COPPER BY POTENTIODYNAMIC POLARIZATION, AC IMPEDANCE AND SURFACE-ENHANCED RAMAN-SPECTROSCOPIC TECHNIQUES

The inhibition effects of benzotriazole (BTA) and 6-aniline-1,3,5-triazine-2,4-dithiol (ATD) monosodium salt on copper corrosion have been studied by the potentiodynamic polarization, AC impedance and surface-enhanced Raman spectroscopic techniques. The polarization resistance R(p) increases with the concentration of either BTA or ATD. From the plots of the phase shift-theta versus logarithm of the frequency, it is found that theta is close to 90-degrees after the copper electrode is immersed for a long period of time in BTA-containing solution which indicates the behavior of an ideal capacitor. In ATD-containing solutions, theta is close to 45-degrees which shows the appearance of a Warburg impedance for a diffusion process. Surface-enhanced Raman spectroscopic studies of the competitive adsorption of BTA and ATD on copper surfaces indicate that BTA adsorbs better than ATD. Based on these results, it is concluded that the inhibition action of BTA is better than that of ATD.