Abstract:
The adsorption behaviour of three Mannich bases [3-(4-chlorophenylimino)-1-(piperidin-1-
ylmethyl)indolin-2-one{M-1}, 3-(4-chlorophenylimino)-1-(morpholinomethyl)indolin-2-one{M-2}
and 3-(4-chlorophenylimino)-1-[(dibutylamino)methyl]indolin-2-one{M-3}] on mild steel surface in
1M HCl solution was investigated using electrochemical impedance spectroscopy (EIS), polarization
curves, and weight loss techniques. The experimental results showed that all Mannich bases are good
inhibitors showing >90% inhibition efficiency. Potentiodynamic polarization measurements showed
that all studied inhibitors are mixed type. Further, quantum chemical calculations were carried out and
the relations between computed parameters and corrosion inhibition efficiency have been discussed.
