Halogen-substituted imidazoline derivatives as corrosion inhibitors for mild steel in hydrochloric acid solution

Two novel imidazoline derivatives, 2-(2-trifluoromethyl-4,5-dihydro-imidazol-1-yl)-ethylamine (1-IM) and 2-(2-trichloromethyl-4,5-dihydro-imidazol-1-yl)-ethylamine (2-IM), have been investigated as corrosion inhibitors for mild steel in 0.5M HCl solution by weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) tests. The surface morphology of sample was presented through scanning electron microscope (SEM) and the inhibition mechanism was elucidated by measuring the potential of zero charge (E_pzc) at the solid/liquid interface. Results of theoretical calculation confirm that the chloride-substituted compound shows better inhibitive performance than the fluoride-substituted one.