ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

1,7′-dimethyl-2′-propyl-1H,3′H-2,5′-bibenzo[d]imidazole as a corrosion inhibitor of mild steel in 1 M HCl

Niketan S. Patel, Smita Jauhari, and Girishkumar N. Mehta

Applied Chemistry Department, Sardar Vallabhbhai National Institute of Technology, Surat, 395007, Gujarat, India

E-mail: niketan.ptl@gmail.com

Received: 2 June 2009  Revised: 27 July 2009  Accepted: 19 August 2009

Abstract: Inhibition effect of imidazole derivative 1,7′-dimethyl-2′-propyl-1H,3′H-2,5′-bibenzo[d]imidazole (DPBI) against mild steel corrosion in 1 M HCl solutions was evaluated using the conventional mass loss method, potentiodynamic polarization, linear polarization, and electrochemical impedance spectroscopy. The mass loss results showed that DPBI is an excellent corrosion inhibitor; electrochemical polarizations data revealed the mixed mode of inhibition; and the results of electrochemical impedance spectroscopy showed that the change in the impedance parameters, charge transfer resistance, and double layer capacitance with the change in the concentration of the inhibitor is due to the adsorption of the molecule leading to the formation of a protective layer on the surface of mild steel. The inhibition action of this compound was assumed to occur via adsorption on the steel surface through the active centers of the molecule.

Keywords: imidazole - acid corrosion inhibitor - electrochemical impedance spectroscopy - mild steel

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-009-0096-5

Chemical Papers 64 (1) 51–55 (2010)