A Promising Water-Soluble Synthetic Polymer of High Efficiency and Low Cost as Inhibitor for Inhibition of Metals Corrosion: Inhibition of Magnesium Corrosion by Poly (Ethylene Glycol) in Acidic Media

Corrosion inhibition of magnesium (Mg) in hydrochloric acid by poly (ethylene glycol) (PEG) as a water-soluble synthetic polymer has been investigated by both gasometric and weight-loss techniques. A comparable value has been observed from the results obtained from those both two techniques. The inhibition efficiency was found to increase with increasing the inhibitor concentration. The kinetic data were found to fit both Langmuir and Freundlich relationships, but the inhibition action was exhibited in the Freundlich isotherm model. Factors affecting the corrosion rates such as the concentration and geometrical structure of inhibitor, concentration of the corrosive medium, and temperature were examined. The inhibition effect of the PEG on the magnesium metal surface was confirmed by Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM), and X-ray diffraction (XRD) techniques. The kinetic parameters were evaluated and a suitable corrosion mechanism consistent with the kinetic results is discussed.