In this chapter, the authors present a synthesis of some works carried out within the framework of the study of the corrosion inhibiting activity of a set of monosaccharide derivatives as new biodegradable, nontoxic corrosion inhibitors, and respectful of the environment. The comparative study that they present reveals the existence of more than 20 compounds derivatives of monosaccharide used as corrosion inhibitors in neutral and acidic mediums, and which have given rise to very good corrosion inhibiting efficiencies. These studies of the corrosion inhibiting effect were studied using potentiodynamic polarization curves and electrochemical impedance spectroscopy methods.
Top1. Introduction
Most of the objects used in our daily life are made of metals, because these latter have several uses due to their physical properties, such as electrical conduction, thermal conduction and resistance to mechanical shocks, in particular iron and its derivatives (carbon steels) (Nam et al., 2012; Tecuapa-Flores et al., 2019; Cruz-Borbolla et al., 2017). However, a high percentage of the quantity of steel used is damaged by corrosion in unsuitable environments, in particular in acidic environments (Rbaa et al., 2019a). These are the reasons why researchers are still trying to find solutions to combat this phenomenon of inappropriate degradation.
Among the proposed solutions, there is the protection of coatings, protection against oxidation and protection against corrosion (Laabaissi et al., 2019; Rbaa et al., 2019b). Currently, researchers are focusing more on inhibiting corrosion because it has the advantage of being the simplest and most economical technique (Fergachi et al., 2019; Rbaa et al., 2019c). Protection against corrosion is based on the use of organic or inorganic chemical compounds, but unfortunately these later sometimes show signs of toxicity during or after use (Martin, 2001; Schüürmann et al., 2011). Also, the application of synthetic compounds as corrosion inhibitors is limited because of the increasing ecological awareness and strict environmental regulations as most of the traditional corrosion inhibitors are synthesized using expensive and toxic chemicals and solvents. In view of this, recently, glucose and their derivatives are being used as corrosion inhibitors as they are available at the economic and commercial level (Han, 2010). Because of the natural and biological origin they can be regarded as one of the greenest sources of the chemical compounds used as corrosion inhibitors. More so, the presence of numerous polar functional groups such as –OH further enhance their corrosion inhibition effectiveness by increasing their molecular size as well as increase solubility in the polar electrolytes. These polar functional groups can also serve as adsorption centers during the meta-inhibitor interactions. Looking the greenness of glucose and their derivatives along with their high protection efficiency, the synthesis, characterization and utilization in all fields of science and technology, including in the area of metallic corrosion inhibition should be further explored (Zhang et al., 2018).
In order to preserve the health of users of these chemical compounds when applied to corrosion inhibition tests, it is desirable to use non-toxic and biodegradable chemicals. Several international organizations and committees have spoken out against the use of toxic chemical products (Han et al., 2010; Zhang et al., 2018). In particular the World Health Organization (WHO) (Teissedre t al., 2000), which is the most active on this side (Rbaa et al., 2020a).
In order to meet the standards of the World Health Organization (WHO), in this study, we have strategically developed the synthesis of two new compound derivatives of D-glucose biodegradable and non-toxic as corrosion inhibitors for steel in 1.0 M HCl. The anticorrosion effect of these two compounds was studied using electrochemical methods such as Potentiodynamic Polarization and Impedance Spectroscopy methods.