Fatty Acids and its Derivatives as Corrosion Inhibitors for Mild Steel - An Overview

Steel is the most important engineering and construction material in the world. Corrosion problems have received a considerable amount of attention because of their attack on materials. Corrosion not only has economic implications, but also social and these engage the safety and health of people either working in industries or living in nearby towns. The use of inhibitors is one of the most practical methods for protection against corrosion. Organic compounds are investigated as corrosion inhibitors, but unfortunately most of these compounds are not only expensive but also toxic to living beings. Fatty acids extracted from plants have become an environmentally acceptable, readily available and renewable source for inhibitors. Many corrosion inhibitor molecules were synthesized by derivatization of fatty acids which was extracted from vegetable oils. Review of literature indicated that the derivatives of fatty acids like ethyl ester, ethoxylate, sulfate, imidazoline, sulfate-amine salt, hydrazides, thiosemicarbazides, phenyl hydrazides, triazoles, oxadiazoles,phenyl thiosemicarbazide etc. were the effective corrosion inhibitors for mild steel in aggressive media.