1-(2-Dodecylsulfanyl-ethyl)-1H-imidazole (DSEIm) and 2-Imidazol-1-yl-ethylsulfanyl)-
acetic acid (ImESAA) were synthesized via radical catalysis method and
characterized using 1H NMR and 13C NMR spectroscopy. The corrosion performances
of mild steel specimens were studied by three imidazole derivatives include: 1-
vinylvinylimidazole (VyIm), DSEIm and ImESAA, which were investigated in 1.0 M
HCl using weight loss measurements, potentiodynamic polarization and electrochemical
impedance spectroscopic (EIS) method. The results obtained show that DSEIm is the
best corrosion inhibitor; its inhibition efficiency (E %) increases with increasing the
inhibitor concentration, but decreases with the raise of temperature. Potentiodynamic
polarization studies clearly revealed that the inhibitors changed the mechanism of
hydrogen evolution, and that they acted as mixed inhibitors, but most effectively in the
cathodic range. The higher values of activation energy (Ea) in the inhibited solution can
be correlated with the increased thickness of the double layer; this is interpreted with
physical adsorption of the inhibitor onto the metal surface resulting in the formation of a
surface film. Adsorption of imidazole derivatives have been studied with Monte Carlo
simulations.
Keywords: Adsorption, Aluminium, Corrosion Inhibition, Cefuroxime axetil, SEM.