NISCAIR Online Periodicals Repository

Research Journals >
Indian Journal of Chemical Technology (IJCT) >
IJCT Vol.13 [2006] >
IJCT Vol.13(3) [May 2006] >

Title: Ternary inhibitor system containing phosphonate, molybdate and Zn2+ in corrosion control of carbon steel
Authors: Rao, B V Appa
Christina, K
Keywords: N-(2-hydroxyethyl)imino-bis(methylphosphonic acid)
Corrosion inhibition
Issue Date: May-2006
Publisher: CSIR
IPC CodeC23F13/00
Abstract: With the objective of developing a new environmental friendly inhibitor formulation for corrosion of carbon steel in nearly neutral aqueous environments, phosphonic acid viz., N-(2-hydroxyethyl) imino-bis(methylphosphonic acid) [HEIBMPA] was chosen as the inhibitor. Zn2+ was chosen as the first synergist. A maximum inhibition efficiency of 99.3% was obtained with the binary system containing 70 ppm HEIBMPA and 80 ppm Zn2+. Molybdate ion, which is inorganic in nature but environmental friendly, was used as the second synergist. The binary inhibitor formulation containing relatively low concentrations, viz., 30 ppm HEIBMPA and 40 ppm Zn2+ offered an inhibition efficiency of only 23%. To the above combination, when 200 ppm molybdate was added, the inhibition efficiency was found to increase to 95%. The potentiostatic polarization studies revealed that this ternary inhibitor system controlled the anodic reaction predominantly. A large increase in the polarisation resistance (Rp) value indicated the formation of a non-porous protective film on the metal surface. The reflection absorption FT-IR spectrum and X-ray photoelectron spectra of the film suggested that the film consisted of [Fe(III)-HEIBMPA-molybdate] complex, [Fe(III), Zn(II)-HEIBMPA-molybdate]complex, oxides and hydroxides of iron and Zn(OH)2. A plausible mechanism of inhibition of corrosion is proposed, which explains all the above experimental results.
Page(s): 275-282
ISSN: 0975-0991 (Online); 0971-457X (Print)
Source:IJCT Vol.13(3) [May 2006]

Files in This Item:

File Description SizeFormat
IJCT 13(3) 275-282.pdf327.63 kBAdobe PDFView/Open
 Current Page Visits: 1255 
Recommend this item


Online Submission of Articles |  NISCAIR Website |  National Knowledge Resources Consortium |  Contact us |  Feedback

Disclaimer: NISCAIR assumes no responsibility for the statements and opinions advanced by contributors. The editorial staff in its work of examining papers received for publication is helped, in an honorary capacity, by many distinguished engineers and scientists.

CC License Except where otherwise noted, the Articles on this site are licensed under Creative Commons License: CC Attribution-Noncommercial-No Derivative Works 2.5 India

Copyright © 2015 The Council of Scientific and Industrial Research, New Delhi. All rights reserved.

Powered by DSpace Copyright © 2002-2007 MIT and Hewlett-Packard | Compliant to OAI-PMH V 2.0

Home Page Total Visits: 167640 since 01-Sep-2015  Last updated on 28-Jun-2016Webmaster: