Available online www.jocpr.com Journal of Chemical and Pharmaceutical Research, 2015, 7(9):712-720 Research Article ISSN : 0975-7384 CODEN(USA) : JCPRC5 712 Influence of a derivative of cyclotriphosphazene as a corrosion inhibitor for carbon steel in 3% NaCl medium Omar Dagdag 1* , Mustapha El Gouri 1,2 , Mouhsine Galai 3 , Mohamed Ebn Touhami 3 , Azzouz Essamri 4 and Ahmed El Harfi 1 1 Laboratory of Polymers, Radiation and Environment- Team of Macromolecular & Organic Chemistry, Department of Chemistry, Faculty of Science, University Ibn Tofail, Kenitra, Morocco 2 Laboratory of Sciences and Techniques of Process Engineering, Department of Process Engineering, Height School of Technology, Sidi Mohammed Ben Abdallah, Fez, Morocco 3 Laboratoire de Matériaux, d’Electrochimie et d’Environnement (LMEE), Département de Chimie, Faculté des Sciences, Université Ibn Tofail, Kenitra, Morocco 4 Laboratory of Agroressources and Process Engineering, Department of Chemistry, Faculty of Sciences, University Ibn Tofail, Kenitra, Morocco _____________________________________________________________________________________________ ABSTRACT Hexa propylene glycol cyclotriphosphazene(HPGCP)was used as corrosion inhibitor and its inhibiting action on the corrosion of carbon steel in 3% NaCl solution was investigated using weight loss test potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) techniques method has been employed in this study. Results indicated that the HPGCP compound acted as an anodic inhibitor. The inhibition efficiency of carbon steel increased with increasing concentrations of the inhibitor. Key words: Carbon steel, corrosion test, weight loss, electrochemical measurements and anodic inhibitor. _____________________________________________________________________________________________ INTRODUCTION Iron and its alloys are widely used in many industrial and engineering applications, including construction, where they are deployed in various service environments containing acids, alkalis and salt solutions. These service environments may easily lead to an inevitable corrosion of metal exposed surfaces because of their aggressiveness [1]. Several techniques were applied to reduce the corrosion rate for metals. The use of inhibitors is one of the most convenient methods for the protection against corrosion in 3% NaCl [2-8]. Most inhibitors are heterocyclic compounds containing in their structure heteroatoms such as nitrogen, oxygen, sulfur and phosphorus [9-12]. These compounds can certainly form either a stronger coordination bond with a metal atom or a passive film on the surface [13]. The inhibition of metal corrosion can involve either physisorption or chemisorption of the inhibitor on the metallic surface. The electrostatic attraction between the hydrophilic groups, which are responsible and active centers for the metal surface, leads to physisorption. Several authors have shown that most of the inhibitors have been adsorbed on the metal surface by displacement of water molecules from the surface and forming a protective film forming a very compact barrier [14].