Inhibition Effects of Chloroquinolines on Corrosion of Mild Steel in Hydrochloric Acid Solution

The corrosion inhibition efficiencies of four compounds namely N-[(1E)-(2-chloroquinolin-3-yl) methylene]-N-phenylamine(CQMA), N-(1E)-(2-chloroquinolin-3-yl) methylene]-N-(4-fluorophenyl) amine (CQMFA), N-(4-chloro phenyl)-N-[(1E)-(2-chloroquinolin-3-yl) methylene]amine (CQMCA), and N-(4-bromo phenyl)-N-[(1E)-(2-ehloroquinolin-3-yl) methylene]amine (CQMBA) on mild steel corrosion in hydrochloric acid media were investigated using mass loss, potentiodynamic polarization and electrochemical impedance spectroscopy. For all the studied inhibitors the inhibition efficiency values were found to increase with increasing concentration up to 5.00 × 10−4 mol · dm−3. Scanning electron microscopic technique showed the formation of a thick film on the steel surface in the presence of inhibitors.