Inhibition effect of Tantum Rosa drug on the corrosion of copper in 3.5 wt.% NaCl solution

Abstract

In the present paper, the inhibition performance of benzydamine hydrochloride drug, commercially named Tantum Rosa on copper was investigated in 3.5 wt.% NaCl solution. Potentiodynamic polarization, electrochemical impedance spectroscopy, scanning electron microscopy and energy dispersive X-ray spectroscopy were employed. The electrochemical results revealed that Tantum Rosa acts as a mixed-type inhibitor on the copper corrosion and its protective effectiveness is concentration and time-dependent. The inhibiting efficiency of Tantum Rosa was improved with the increase in the drug concentration and reached the maximum value of 91.5% at 5 mM. The inhibitive effect of Tantum Rosa was afforded to its spontaneous adsorption on the copper surface, through combined physical and chemical processes, according to Langmuir adsorption isotherm. The time-weakening of the inhibitor film stability leaded to a progressive decay of the inhibition ability of Tantum Rosa at prolonged exposure. SEM-EDX analysis confirmed that the surface morphology of copper was significantly improved in the presence of the inhibitor.