A comparison of the inhibitory activity of 3-alkyland 3-hydroxyalkyl-5-amino-1H-1,2,4-triazoles against copper corrosion in chloride-containing environments

Abstract

Copper is widely used as a material for technical solutions in microelectronics, as well as for the manufacture of various heat exchange equipment used in aggressive environments. Corrosion inhibitors are used for the reduction of the corrosive activity of the environment. This article presents the results of a study of the anticorrosion activity of a number of derivatives of the class 3-alkyl- and 3-hydroxyalkyl-5-amino-1H-1,2,4-triazole with respect to copper corrosion in chloride-containing environment. Over the course of the study, 3-alkyl- and 3-hydroxyalkyl-5-amino-1H-1,2,4-triazoles with different lengths of the alkyl substituent were synthesized. The structure of these compounds was confirmed using NMR spectroscopy and HPLC/MS analysis. Based on the results of electrochemical and direct corrosion tests, regularities were established for the inhibitory activity of the obtained compounds in acidic (1% HCl solution) and neutral (borate buffer solution, pH = 7.4) chloride-containing media. In in a neutral media, the greatest protective effect was obtained for 3-propyl-5-amino-1H-1,2,4-triazole I, which has the shortest alkyl radical without modification by an OH group. As the concentration increased in the range from 0.01 to 10.0 mmol/L, the inhibitory activity increased. With an increase in the length of the alkyl radical and/or the introduction of an OH group, a decrease or absence of a protective effect was observed. At the same time, in an acidic medium, the introduction of a hydroxyl group into the alkyl substituent of 5-amino-1H-1,2,4-triazole increased anti-corrosion efficiency only with sufficient length of the carbon chain. The highest protection degree was obtained for 17-(5-amino-1H-1,2,4-triazol-3-yl)heptadecan-7-ol IV at a concentration of 10.0 mmol/l and it reached a value of 97%.

Keywords

• metal corrosion
• copper
• corrosion inhibitors
• heterocyclic compounds
• aminotriazoles
• physico-chemical research methods