Abstrato

Study on the Effect of Musa Acuminata Flower Extract on the Corrosion Inhibition of Mild Steel in 1 N H2SO4

N. Gunavathy and S. C. Murugavel

The corrosion inhibition performance of Musa acuminata flower [MAN (F)] extract on mild steel in 1 N sulphuric acid solution was monitored by weight loss measurements and electrochemical technique like potentiodynamic measurement for various concentrations of the extract and in the temperature range 303 K to 353 K. The inhibition efficiency of MAN (F) extract increased with the increase of concentration but decreased with the increase in temperature. Inhibitor showed a maximum efficiency of 95.01 % at 2 % v/v extract concentration for 5 hours immersion. The polarization curves indicated that MAN (F) acts as a mixed type inhibitor. Electrochemical impedance spectroscopy studies showed the change in charge transfer capacitance with the change in concentration of the flower extract. The Temkin adsorption isotherm was tested for its fit to the experimental data. Results of SEM study on the surface morphology of mild steel in uninhibited and inhibited acid solution showed that the corrosion rate is reduced to a low value in the presence of the inhibitor. This may be due to adsorption of inhibitor molecules on the surface as a protective layer preventing acid attack. A mechanism of physical adsorption of the phytochemical components on the surface of the metal is proposed for the inhibition mechanism.