Mild steel corrosion inhibition in 200 ppm NaCl by new surfactants derivatives of bis-glucobenzimidazolones

Arabian Journal of Chemistry, Available online 14 December 2013, In Press, Accepted Manuscript (Open Access)
Mild steel corrosion inhibition in 200 ppm NaCl by new surfactants derivatives of bis-glucobenzimidazolones
Laila Lakhrissi (a),  (c), Brahim Lakhrissi (a), Rachid Touir (b), Mohamed Ebn Touhami (b), Mohamed Masoui (c), Mohamed Essassi (c)
a Laboratoire d’Agroressources et Génie des Procédés, Faculté des Sciences, Université Ibn Tofail, BP 133, Kénitra 14000, Morocco
b Laboratoire de Matériaux, Electrochimie et Environnement, Faculté des Sciences, Université Ibn Tofail, BP 133, Kénitra 14000, Morocco
c Laboratoire de Chimie Organique Hétérocyclique, Université Mohammed V - Agdal, Faculté des Sciences, Rabat, Morocco
Abstract
The new bis-glucobenzimidazolone derivatives (24a-d) have been synthesized and characterized by NMR spectroscopic. They have been tested as corrosion inhibitor for mild steel in 200 ppm NaCl solution using potentiodynamic polarization curves and electrochemical impedance spectroscopy. Potentiodynamic polarization curves measurements showed that the investigated compounds were a mixed-type inhibitor. Their inhibition efficiencies improve with concentration and reached a maximum at 10-5 M of each compounds and the 24b is the better. Electrochemical impedance spectroscopy measurements showed that the diagrams composed of two depressed capacitive loop. This loop can be split into two capacities’ contributions, although badly separated. The first loop is attributed to the formation of a protective layer and the second is attributed to the charge transfer resistance.
1. Introduction
Corrosion process plays an important role in the field of economics and safety. Various types of steel including iron and its alloys included in different industries (Chemical and Electrochemical industries, Medical, Nuclear, Petroleum, Power, and Food Production), and also in daily life. However, it suffers from a certain type of corrosion within some environments. Due to the aggressiveness of some medium, corrosion can be reduced by the addition of corrosion inhibitors in small concentrations. Most commercial inhibitors are organic compounds containing in their structure heteroatoms such as nitrogen, oxygen and sulfur (Zarrouk et al., 2012, Deng et al., 2011, Cenoui et al., 2010, Ramesh et al., 2003 and Labriti et al., 2012). These compounds can form either a strong coordination bond with metal atom or a passive film on the surface (Gogoi and Barhai, 2010). There is still a continuous investigation for better inhibitors or blend of inhibitors to meet the demand of the industry. The selection criteria for various inhibitors include low concentration, stability in recirculation, cost effectiveness and low operational hazard.
However, benzimidazolone derivatives constitute an important class of benzoheterocycles, which constitute the building blocks of wide range of therapeutic, biological and industrial properties (Baragatti et al., 2000, Olesen et al., 1994, Zhang et al., 2001, Biagi et al., 2001, Singh et al., 2001 and Torres et al., 2003). Also, some derivatives have been reported to show complexant properties (Htay and Meth-Cohen, 1976a, Htay and Meth-Cohen, 1976b, Meth-Cohen et al., 1982 and Cignitti et al., 1995). In our previous work, we have shown that some series of glycobenzimidazolone present an importante amphiphilic property (Lakhrissi et al., 2008, Lakhrissi et al., 2010 and Lakhrissi et al., 2011).
Firstly, the present work is aimed to synthesize and characterize the bis-glucobenzimidazolone derivatives by NMR spectroscopic. A second objective is to evaluate their inhibition effect for mild steel in 200 ppm NaCl using electrochemical techniques.
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