Rajendran, S. and Apparao, B.V. and Palaniswamy, N. (2000) Corrosion inhibition by phosphonic acid – Zn2+ systems for mild steel in chloride medium. Anti-Corrosion Methods and Materials , 47 (06). pp. 359-365. ISSN 0003-5599

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Abstract

The inhibition efficiencies of 2-carboxyethyl phosphonic acid (2 CEPA) – Zn2+ system and ethyl phosphonic acid (EPA) – Zn2+ system in controlling corrosion of mild steel in a neutral aqueous environment containing 60ppm Cl- have been compared. Polarization study reveals that both the systems function as mixed inhibitors. The inhibition system of these systems decrease with period of immersion due to the dissolution of the protective film as the period of immersion increases. The 2 CEPA – Zn2+ system has a better inhibition efficiency than the EPA – Zn2+ system. This is due to the fact that the amount of Fe2+ - 2 CEPA complex present on the metal surface is higher than that of Fe2+ - EPA complex, as revealed by fluorescence spectra. The molecular size of the iron phosphonate complex exercises a greater influence than the electronic (inductive) effect of the substituent in controlling corrosion of mild steel in chloride environment

Item Type:	Article
Uncontrolled Keywords:	Coatings; Corrosion inhibitors; Acids; Mild steel
Subjects:	Corrosion Science and Engineering
Divisions:	UNSPECIFIED
Depositing User:	ttbdu cecri
Date Deposited:	18 Dec 2012 05:58
Last Modified:	18 Dec 2012 05:58
URI:	http://cecri.csircentral.net/id/eprint/2987

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