Two novel Schiff bases derived from 3-amino-1,2,4-triazole as corrosion inhibitors for carbon steel pipelines during acidizing treatment of oil wells: Laboratory and theoretical studies

Two novel Schiff bases derivatives of 1 H-1,2,4-triazole-3-yl)imino (L1 and L2) were synthesized and investigated as corrosion inhibitors for carbon steel in 1 M HCl solution. The corrosion inhibition efficiency of L1 and L2 was inspected by gravimetric measurements, electrochemical method, and quantum chemical calculations. L1 and L2 inhibitory efficiency is related to the test's concentration. The created compounds were characterized using Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR) analysis. The corrosion inhibition property of the synthesized Schiff base on carbon steel, the main component of pipelines used in oil and gas fields, in 1 M HCl medium was investigated using weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy (EIS). From the loss-weight data it was found the inhibition rises by the grown inhibitor concentration, which at 1 mM of L1 and L2, receiving a record level in eta (w) of 92.3% and 93.9%, respectively. The prepared Schiff bases act as good mixed-type corrosion inhibitors, according to potentiodynamic polarization experiments. Both inhibitors' adsorption on CS surfaces followed the Langmuir adsorption isotherm, with both physisorption and chemisorption. The impact of the molecular structure of the synthesized Schiff bases was examined using the density-functional theory (DFT) method and molecular dynamic (MD) simulation.