The College of Education for Pure Sciences, Department of Chemistry, University of Basra, discussed a doctoral thesis on the title of the thesis
Preparation and characterization of new azo dyes and their complexes derived from 3-tert-butyl-4-hydroxyanisol and evaluation of some dyes as corrosion inhibitors for carbon steel in acidic medium.
The thesis submitted by the researcher (Hanadi Mahdi Jarallah) included
In this study, new azo compounds derived from the coupling of diazonium salts of amines substituted with (3-tert-butyl-4-hydroxyanisol) were prepared. ) from the metal ion to the ligand.
The prepared compounds were diagnosed using infrared spectroscopy, ultraviolet spectroscopy, proton and carbon nuclear magnetic resonance, mass spectrometry, microelement analysis, molar conductivity, thermal analyzes and magnetic sensitivity, and the percentage of metals included in their composition was calculated using the Flame AAS technique. The practical values ​​were close to the calculated theoretical values ​​for metals.
In addition to the above, some compounds were used as corrosion inhibitors for carbon steel in an acidic medium (1 M) of aqueous solution of HCl and at temperatures (298 - 318 K) in the absence and presence of inhibitors (L1, L5, L6) and at different concentrations using the dynamic polarization method. (Tafel plot).
The thermodynamic functions such as activation energy (Ea), free energy (∆G), enthalpy (∆H) and entropy (∆S) were also calculated, as it was found that the adsorption of the inhibitor on the metal surface is subject to the Lanckmierre adsorption model. The adsorption process of corrosion inhibitors is of mixed type.
Objectives of the study
Preparation of azo compounds and evaluation of some compounds as corrosion inhibitors for carbon steel in acidic media.
Conclusions
The prepared compounds act as corrosion inhibitors, and the results showed that the compound containing N, O and S atoms gave a higher inhibition efficiency than the compounds containing only N and O atoms. Inhibition efficiency increases with increasing concentrations of the inhibitor to reach maximum values ​​of (89.18, 81.14). , 78.4% for the L6, L1 and L5 inhibitors, respectively. The adsorption of the inhibitors on the metal surface is subjected to a Lankmire model.