Sulfur and phosphorus heteroatom‐containing compounds as corrosion inhibitors: An overview

Abstract

Use of organic compounds containing nitrogen (N), oxygen (O), sulfur (S), and phosphorus (P) heteroatoms in their molecular structures is one of the most effective, economic, and practical corrosion inhibitors. The effectiveness of the heteroatoms toward metallic corrosion inhibition follows the order: P > S > N > O. The metal‐inhibitor interactions involve the charge sharing between the heteroatoms and empty d‐orbitals of the surface metallic atoms; therefore, a heteroatom with lower electronegativity value is more potent to form strong bonding (charge sharing) with metallic surface as compared to more electronegative heteroatom. Literature study reveals that almost all corrosion inhibitors have either one or more heteroatoms in their molecular structures particularly in the form of polar functional groups, which enhance their adsorption tendency on metallic surface. Present review paper features the collection of some major works that have been published on metallic corrosion inhibition containing these P, S, O, and N heteroatoms. Since now, several review articles have been published describing the application of N and O atoms; however, the reviews on use of P and S heteroatoms are scare. Therefore, aim of the present article was to mainly describe the collection of corrosion inhibitors containing S and P heteroatoms.

Corrosion inhibition of copper in ferric chloride solutions with organic inhibitors

“…Here, the values of ÀΔG ads for BTA, MBTA, and MBI were between 24 and 28 kJ mol -1 , the value for MBI being most negative. The negative values indicate spontaneous adsorption of the inhibitor molecules on the Cu surface, namely the interaction between the inhibitor molecules and the metallic surface is stronger than the interaction between the metallic surface and water molecules 55 . The values themselves suggest that the adsorption of the three inhibitors took place neither via pure physisorption nor via pure chemisorption, but via a combination of both (i.e., physiochemisorption 55 ).…”

“…The orientation of the molecule relative to the surface can have its own effect, as described elsewhere 67 . The role of heteroatoms such as N and S in the interaction between organic inhibitor compounds and metallic surfaces has also been described in detail elsewhere 55 .…”

Evaluating the performance of Andrographis paniculata leaves extract as additive for corrosion protection of stainless steel 316L in seawater

“…As the major component, it has multiple bonds which can be assumed to be able to aid the adsorption process of the coating onto the stainless steel surface. The assumption is due to the action of heteroatom when exposed to an aggressive environment will be protonated thus inducing the reaction between compounds of the extract with the substrate [30]. Moreover, in order to achieve the noble state of orbit, the phenolic group of andrographolide would donate electrons to the metal.…”

Highly durable macromolecular epoxy resin as anticorrosive coating material for carbon steel in 3% NaCl: Computational supported experimental studies

“…Corrosion is an instinctive property of most of the metals that is allied with massive security and monetary fatalities. According to the statistical classification of economic activities in the European Community (NACE), the annual global cost of corrosion has reached nearly $ 2.5 trillion USD, which represents about 4.2% of total GDP (Gross Domestic Product) . Therefore, corrosion inhibition is an extremely essential demand especially in industrial sectors.…”