Mechanism of inhibition of iron corrosion in hydrochloric acid by pyrimidine and series of its derivatives

H.S. Awad (Chemistry Department, Faculty of Girls for Science, Art and Education, Ain Shams University, North York, Ontario, Canada)
S. Abdel Gawad (Chemistry Department, Faculty of Science, Cairo University, Cairo, Egypt)

Anti-Corrosion Methods and Materials

ISSN: 0003-5599

Publication date: 1 December 2005



To investigate the capability of a series of nitrogen‐based heterocyclic organic compounds in inhibiting corrosion of iron in HCl and elucidate the dominant active form of the applied compounds during the adsorption process to explore the mechanism of their action.


The tested compounds were pyrimidine containing compounds, which were selected, based on molecular structure considerations. Gravimetric method has been applied with various electrochemical techniques (polarisation resistance, polarisation curves and electrochemical impedance spectroscopy) to investigate inhibition efficiency and mechanism.


The inhibiting action of the investigated pyrimidine containing compounds depends primarily on their concentration and molecular structure. These compounds act as mixed type inhibitors and function via adsorption on the surface, which follows Frumkin adsorption isotherm. The inhibition by the tested pyrimidine derivatives could be attributed to their chemisorption on the metal surface forming donor/acceptor type of bond between the inhibitor molecules and the vacant d orbitals of the surface iron atoms. Contribution from electrostatic adsorption, via interaction between the protonated form of the inhibitor and the charged metal surface, is also possible.

Research limitations/implications

The applied inhibitors were tested in the presence of chloride ions as a corrosive medium. Whether these inhibitors will function well in the presence of other ions that are typically present in natural corrosive environment is unknown.


This paper provides useful information regarding inhibition effect of pyrimidine and series of its derivatives. The outcome of this work contributes to better understanding of the mechanism of inhibition by this class of N‐based heterocyclic organic compounds.



Awad, H. and Abdel Gawad, S. (2005), "Mechanism of inhibition of iron corrosion in hydrochloric acid by pyrimidine and series of its derivatives", Anti-Corrosion Methods and Materials, Vol. 52 No. 6, pp. 328-336.

Download as .RIS



Emerald Group Publishing Limited

Copyright © 2005, Emerald Group Publishing Limited

Please note you might not have access to this content

You may be able to access this content by login via Shibboleth, Open Athens or with your Emerald account.
If you would like to contact us about accessing this content, click the button and fill out the form.
To rent this content from Deepdyve, please click the button.