hree nonionic surfactant (NIS) compounds containing five membered heterocyclic moiety were synthesized and identified from spectral data such as IR and 1HNMR spectra.
The inhibiting effect of NIS compounds toward the corrosion of aluminium (Al) in 1.0MHCl
solutions was examined using weight loss, thermometric, electrochemical impedance spectroscopy and galvanostatic polarization techniques. The results obtained indicated that the
three compounds are good corrosion inhibitors. The inhibition efficiency increases as the
concentration of the NIS compounds increases, as well as the decrease in temperature,
surface tension and interfacial tension. The polarization measurement showed that these
inhibitors are acting as mixed inhibitors mainly cathodic. The inhibition was interpreted in
view of spontaneous adsorption of NIS compounds onto the Al surface by forming a stable
chelating ring between the Al surface and NIS molecules. The adsorption mechanism obeys
Freundlich isotherm. The activated thermodynamic parameters such Ea, H∗ and S∗were
calculated and clarified.