Original Articles: 2012 Vol: 4 Issue: 12
Aromatic Amines as Corrosion Inhibitors for Zinc in Hydrochloric Acid
Abstract
The inhibition of corrosion of zinc in hydrochloric acid by aromatic amines like, aniline, o- toluidine, m- toluidine, p- toluidine and p- chloroaniline has been studied with respect to inhibitor concentration and temperature. The inhibition efficiency of aromatic amines increased as the concentration of the inhibitor increased, while decreased with the increase in concentration of the acid and temperature. Weight loss data at different temperatures was used to determine activation energy. The activation energies in inhibited acid are higher than that in plain acid. For all inhibitors, the heat of adsorption (DHads) and free energy of adsorption are negative. The plot of log (q/1-q) versus log C results in a straight line, suggest that, the inhibitors appears to function through adsorption following Langmuir isotherm. Galvanostatic polarization curves show polarization of both anodes as well as cathodes.