Corrosion Inhibition of Alkyl Imidazoline on Copper in Hydrochloric Acid Solution

The corrosion inhibition behavior of 2-undecyl-N-carboxymethyl-N-hydroxyethyl　imidazoline (UHCI) on copper in 5% HCl solution was studied using Tafel polarization , electrochemical impedance spectroscopy(EIS) and cyclic voltammetry(CV). The results indicate that UHCI is an effective inhibitor in protecting copper from corrosion in hydrochloric acid solution, the inhibition efficiency increased with the increased concentration of UHCI, until the concentration of UHCI reached 0.15%, imidazoline behaves as a mixed type inhibitor and hinders both the anodic oxidation and cathodic reduction processes. Quantum chemical calculations indicate that O(14) offers electrons to form coordinate bond with copper and the adsorption of the molecules of inhibitor is chemisorption on the surface of copper.