Corrosion inhibition performance of a structurally well-defined 1,2,3-triazole derivative on mild steel-hydrochloric acid interface

Abstract

In the present work, a new 1,4-disubstituted-1,2,3-triazole product, named 4-[1-(4-methoxy-phenyl)-1H-[1,2,3]triazol-4-ylmethyl]-morpholine (MPTM) was successfully synthesized under click chemistry regime. The structure of the new compound that has a rigid triazole moiety and a flexible morpholine ligand has been characterized using 1H NMR, 13C NMR, HRMS, and FTIR spectroscopy. Its inhibition performance for mild steel in acidic medium 1 M HCl has been studied by utilizing a combination of experimental, spectroscopic and computational methods. The electrochemical characterization was carried out by a gravimetric study, electrochemical impedance spectroscopy (EIS), and potentiodynamic polarization (PDP) measurements. The MPTM exhibits a high corrosion inhibition efficiency of 94% with 900 ppm at 298 K. Adsorption of MPTM on the mild steel surface followed the Langmuir isotherm. Data obtained from the surface analysis by scanning electron microscopy (SEM), energy dispersive X-ray (EDX), and FTIR spectroscopies evidenced the dual chem- and physi-adsorption of the inhibitor 1,2,3-triazole derivative on the surface of the metal. A quantum chemistry study was performed by means of density functional theory (DFT) to rationalise the adsorption of MPTM and its corrosion inhibition action at the interface of mild steel-hydrochloric acid system, establishing a very good correlation between the molecular structure and its inhibition property.