Inhibition of Carbon Dioxide Corrosion of Mild Steel by Imidazolines and Their Precursors

Corrosion inhibition of mild steel by imidazolines and their precursors in a carbon dioxide (CO2)-containing environment was studied using rotating cylinder electrode (RCE) and linear polarization resistance (LPR) techniques. Corrosion rate-time/concentration profiles and minimum effective concentrations obtained for a series of imidazolines and amides were evaluated in terms of the respective contributions of their constituent parts (imidazoline ring, amide/amine group, and hydrocarbon chain) to overall corrosion inhibition. Formation of the inhibitor film was studied in terms of the bilayer/multilayer film model.