Use of natural gums as green corrosion inhibitors: an overview

Abstract

Corrosion of metals and its alloys employed in service is an inescapable but a controllable process. One of the practical methods for controlling the impact of corrosion of metals and alloys especially in aqueous environments is by using corrosion inhibitors which are composed mainly of organic or inorganic substances. However, the toxicity of organic and inorganic corrosion inhibitors to the environment and humans has compelled the search for safer corrosion inhibitors called 'green corrosion' inhibitor due to their properties like non-toxicity, biodegradability, and low cost. The use of natural gums as environmentally safe corrosion inhibitor for metal and alloys has in recent times received tremendous attention by several researchers. Also quantitative structure activity relationship approach has been used to establish the correlations between a number of quantum chemical parameters and the molecular structures of some gum extracts major components. This approach has aided in understanding the component of the gum extracts responsible for imparting the inhibition effect since there are several components of the gum which could act in synergy to inhibit the metal corrosion. This review paper presents an overview of works published on natural gums as green corrosion inhibitors. It also discusses the use of computational chemistry tools in understanding the inhibition mechanism of gum extracts components which is often difficult to determine using experimental means.

Anticorrosive efficacy and adsorptive study of guar gum with mild steel in acidic medium

“…Gum metal complexes occupy a large surface area, thereby blanketing the surface and shielding the metal from corrosive agents present in the solution. The presence of arbinogalactan, sucrose, oligosaccharides, polysaccharides, and glucoprotein confirms the presence of compounds containing oxygen and nitrogen atoms there, which are the active centers of adsorption (Gardner and Eikerts 1983;Bumgartner et al 1983;Shah and Walters 1984;Peter et al 2015).…”

Potential of Azadirachta indica as a green corrosion inhibitor against mild steel, aluminum, and tin: a review

“…After then, interest in using natural products as corrosion inhibitors increased substantially and scientists around the world reported several plant extracts as promising green anticorrosive agents (Schmitt et al 2009b). Most of the gums were also reported as good corrosion inhibitor due to their gum-metal complex forming capacity, availability of п-electrons and hetero atoms, and less toxic properties (Peter et al 2015). The adsorption of organic molecules depends on the presence of п-electrons and hetero atoms (Jin et al 2006;Raja and Sethuraman 2008a).…”

Theoretical Investigation to Corrosion Inhibition Efficiency of Some Chloroquine Derivatives Using Density Functional Theory

“…The effectiveness of inhibitors has been associated with the electronic structure as well as their spatial orientation. Most effective and efficient inhibitors have -bonds and heteroatoms (P, S, N and O) with lone pair electrons can inhibit the corrosion of metal in aqueous acid solutions [6,7]. The toxic nature of inorganic and organic inhibitors in the environment [7,8] is leading to search for other environmental friendly inhibitors such as green inhibitors.…”

“…Most effective and efficient inhibitors have -bonds and heteroatoms (P, S, N and O) with lone pair electrons can inhibit the corrosion of metal in aqueous acid solutions [6,7]. The toxic nature of inorganic and organic inhibitors in the environment [7,8] is leading to search for other environmental friendly inhibitors such as green inhibitors. Green corrosion inhibitors which include plant extracts and drugs [10][11][12][13][14] are more environmental friendly.…”