1.Department of Chemical Sciences, Federal University, Wukari, Taraba State, Nigeria
2.Department of Chemistry, Adamawa State University, Mubi, Adamawa State. Nigeria
Abstract
Corrosion inhibition of brass in HCl solutions by Ficuscarica and Vitellaria paradoxa leaf extracts was studied using weight loss measurements at 303, 313, 323 and 333K. The adsorption of the inhibitors on brass surface follows Frumkin and Langmuir adsorption isotherms. The effect of temperature indicated that the corrosion rate and inhibition efficiency are temperature dependent in the range 303-333K. The kinetic data obtained indicate that the adsorption follows a first order type of reaction. Physisorption mechanism has been proposed for the inhibitors. Comparative assessment of the inhibitors revealed that Ficuscarica is a better inhibitor (highest %I
E = 84.68%) for brass corrosion than Vitellariaparadoxa (highest I
E = 77.66%). The presence of alkaloids, glycosides, saponins and tannins (having –C=O, C-OH, C=C, OH -CH3, e t c groups) in the plants extracts were found to have contributed greatly to the inhibition process by interacting with the brass surface.