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International Journal of Corrosion
Volume 2012, Article ID 980654, 8 pages
Research Article

Interesting Behavior of Pachycormus discolor Leaves Ethanol Extract as a Corrosion Inhibitor of Carbon Steel in 1 M HCl: A Preliminary Study

1Laboratory of Corrosion and Material, Institute of Engineering, Autonomous University of Baja California, Blvd. Benito Juárez y Calle de la Normal, S/N, 21280 Mexicali, BC, Mexico
2Cortec Corporation, 4119 White Bear Parkway, St. Paul, MN 55110, USA

Received 27 June 2011; Accepted 30 August 2011

Academic Editor: Peter C. Okafor

Copyright © 2012 Ramses Garcia Inzunza et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The purpose of this paper is to evaluate the inhibitive action of an ethanol extract from the leaves of Pachycormus discolor (EEPD) on the corrosion of carbon steel in 1 M HCl at different temperatures; gravimetric method and electrochemical tests were conducted. Potentiodynamic polarization was used at room temperature and resistance polarization at different temperatures. Thermodynamic adsorption parameters are shown in order to demonstrate the spontaneous adsorption. The inhibition of EEPD was performed via adsorption of the extract species on the carbon steel surface. The ethanol extract obeys Langmuir adsorption isotherm. Potentiodynamic polarization results indicate that the ethanol extract acts as a mixed type inhibitor. The results revealed that the inhibition efficiency (IE) of EEPD increases (when the concentration is increased). Phytochemical and FTIR analyses are also presented in this work. It was found that the IE increases with the temperature in a 2.0% v/v solution which showed 94.52% IE at 2 5 C and 97.89% at 7 5 C.