Preparation and evaluation of Azo phenol as corrosion inhibitor for carbon steel in acid solution

Document Type : Review Articles


1 chemical lab sector, Petroleum pipeline company, Mostorod, EGYPT

2 Al-Azhar University, Faculty of science, Chemistry Department

3 Egyptian Petroleum Research Institute, Nasr City, 11727, Cairo, Egypt.

4 chemistry department-al-azhar university


In this work, 2,6-di-tert-butyl-4-(4-iodophenylazo) phenol (Azo) has been prepared. The chemical structure of this Azo compound has been identified via elemental analysis, Fourier transform infrared spectroscopy (FT-IR), 1Hnuclear magnetic resonance spectroscopy (1H NMR), and mass spectrometry. Furthermore, its ability to inhibit the corrosion of carbon steel in 1 M HCl was studied. Various techniques were used to investigate its inhibition efficiency, including potentiodynamic polarization PDP, electrochemical impedance spectroscopy (EIS), and electrochemical frequency modulation (EFM). It is found that the synthesized compound reveals high inhibition efficiency that is increased as the inhibitor concentration increased. The maximum level of inhibition efficiency has been achieved at an inhibitor concentration of 1×10−4 M. The prepared azophenol adsorbed on the steel surface in the form of a mono layer with lateral interlinks between the molecules, according to the adsorption studies. Furthermore, chemisorption is the major adsorption in this situation.


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