Synthesis of the vanillin-modified lauryl imidazoline derivative and its corrosion inhibition properties

The objective of the present study was to investigate the corrosion inhibition effect of two novel imidazoline-derived compounds, namely 2-(2-undecyl-4,5-dihydro-1H-imidazol-1-yl)ethan-1-amine (LI) and (Z)-2-methoxy-5-(((2-(2-undecyl-4,5-dihydro-1H-imidazol-1-yl)ethyl)imino)methyl) phenol (VLI) in 3.5 wt.% NaCl solution. The molecular structures of the two compounds were characterized by 1H-NMR and FT-IR spectroscopy. The corrosion behavior of the two compounds on Q235 carbon steel in 3.5 wt.% NaCl solution and the mechanism of action were systematically investigated using electrochemical techniques, surface analysis methods, and quantum chemical calculations. The results showed that the corrosion inhibition efficiencies of LI and VLI reached 92.75% and 90.1%, respectively, with LI as anodic and VLI as mixed corrosion inhibitors. Theoretical calculations confirmed that the two corrosion inhibitors were adsorbed on the metal surface by physicochemical means.VLI demonstrated superior corrosion inhibition performance compared to LI, which was attributed to its higher adsorption sites, effectively enhancing its adsorption capacity.