3-Alkyl-5-amino-1,2,4-triazoles synthesized from the fatty acids of sunflower oil processing waste as corrosion inhibitors for copper in chloride environments

Aminoazoles and their derivatives are widely used as corrosion inhibitors for metals. The introduction of a hydrophobic substituent into the aminoazole molecule causes a significant increase in inhibition. New promising corrosion inhibitors for copper of 3-alkyl-5-amino-1H-1,2,4-triazoles were synthesized from fatty acids of sunflower oil processing waste by interaction with aminoguanidine under different conditions. New approaches to the application of renewable materials are of indisputable interest for a higher-level of chemical processing of plant oils. The protective effect of 3-alkyl-5-amino-1H-1,2,4-triazoles synthesized from fatty acids against the corrosion of copper in chloride media was studied using polarization curves, electrochemical impedance spectroscopy, and full-scale corrosion testing. It was determined that it is less efficient to directly add the substance to the solution. It is more beneficial to preliminary hold metal in a non-aqueous solution. The most promising application method for 3-alkyl-5-amino-1H-1,2,4-triazoles synthesized from fatty acids is inter-operational protection of copper products. SEM method determined that polarization in presence of the compounds did not cause the formation of pitting. The accelerated corrosion testing in the salt spray cabin demonstrated up to a 70-fold increase in time before corrosion damage. The protection degree in an HCl solution can reach 99%.