Study on the corrosion inhibition performance of imidazoline composite inhibitor

Abstract Imidazoline quaternary‐ammonium‐salt corrosion inhibitor and thioureido‐imidazoline quaternary‐ammonium‐salt compound corrosion inhibitor were synthesized using oleic acid, diethylenetriamine, benzyl chloride, and thiourea as the raw materials. The resulting samples were characterized by static weight‐loss method, electrochemical polarization curve, X‐ray photoelectron spectrometry (XPS), and scanning electron microscope (SEM). The electrochemical characteristics of the inhibitors' inhibition towards carbon dioxide corrosion were investigated, the major constituents of the protective film formed on the surface of A3 carbon steel by thioureido‐imidazoline compound corrosion inhibitor were analyzed, and the corrosion inhibiting mechanism for thioureido‐imidazoline in hypersaline was explored. The results indicated that thioureido‐imidazoline compound corrosion inhibitor had better corrosion inhibiting effect than imidazoline and can efficiently inhibit the corrosion of A3 carbon steel by CO 2 ‐saturated hypersaline water.