INHIBITING EFFECT OF 4-AMINO-8-(4-CHLOROPHENYL)-2-(4-NITROPHENYL)-6-OXO-2,6-DIHYDROPYRIMIDO[2,1-B][1,3]THIAZINE-3,7-DICARBONITRILE ON THE CORROSION OF A CARBON STEEL IN PHOSPHORIC ACID

 

M. Belayachi1, H. Zarrok1, M. Larouj1, A. Zarrouk2*,

H. Bourazmi3, A. Guenbour3, B. Hammouti2,4*, S. Boukhriss5, H. Oudda1

1 Laboratoire des procèdes de séparation, Faculté des Sciences, Université Ibn Tofail, Kenitra, BP 133,

Kenitra, Morocco.

2 LCAE-URAC 18,  Faculté des Sciences,  Université Mohammed Premier, Oujda, Morocco

3 Laboratoire d'Electrochimie, Corrosion et Environnement, Faculté des Sciences, Université Mohammed V,

Rabat, Morocco.

4Chemistry Department, Faculty of Science, Taibah University, Al Madinah Al Mounawara, 30002

Saudi Arabia

5 Laboratoire de Synthèse Organique, Organométallique et Théorique.

Université Ibn Tofail. Faculté des Sciences. B.P 133, Kenitra. Morocco

* Corresponding author. E-mail:  hammoutib@gmail.com 

Received: 13 May 2014; revised version accepted: 09 October 2014

 

Abstract

     The inhibition effect of 4-amino-8-(4-chlorophenyl)-2-(4-nitrophenyl)-6-oxo-2,6-dihydropyrimido[2,1-b][1,3]thiazine-3,7-dicarbonitrile (ACPTC) on the corrosion of carbon steel (CS) in 2.0 M H3PO4 solution at 303-333K was studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. The results show that ACPTC is a good inhibitor, and the maximum inhibition efficiency of 1.0 mM inhibitor is higher than 98% at all studied temperatures. The adsorption of ACPTC obeys Langmuir adsorption isotherm. Polarisation curves show that ACPTC behaves as a mixed-type inhibitor. EIS spectra exhibit one capacitive loop.

 

Keywords: Inhibitor; Carbon steel; H3PO4; EIS; Polarization; Langmuir.

 


 

 

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