Studies on triazole derivatives as inhibitors for the corrosion of muntz metal in acidic and neutral solutions

The influence of few triazole derivatives namely, 4-amino-5-mercapto-3-methyl 1,2,4 triazole (AMMT), 4-amino-5-mercapto-3-methyl 1,2,4 triazole (AMET) and 4-amino-5-mercapto-3-propyl 1,2,4 triazole (AMPT) on the corrosion behavior of muntz metal (60Cu-40Zn) in acidic and neutral solutions has been studied using weight loss measurements and potentiodynamic polarization methods. Surface morphological examinations such as UV spectral analysis, XRD and SEM have also been carried out to understand the mechanism of inhibition of corrosion. All the triazoles derivatives are found to inhibit the corrosion of muntz metal very effectively in both the acidic and neutral solutions. Polarization measurements clearly show that the inhibitors behave as mixed type in neutral medium and are predominantly cathodic nature in acidic solutions. UV spectra, XRD and Scanning Electron Microscopic studies clearly reveal the formation of a strongly adsorbed film on the metal surface, which is responsible for the inhibition of corrosion in both the media. From the above studies, it can be concluded that the inhibition of corrosion by these compounds is due to a chemisorption process. Among these compounds. AMPT is found to offer better corrosion inhibition than the other compounds. (c) 2005 Elsevier B.V. All rights reserved.