Corrosion Inhibition Potential of Daniella Oliverri Gum Exudate for Mild Steel in Acidic Medium

Physicochemical parameters of Daniella olliverri (DO) gum exudates were analyzed and the results indicated that the gum is acidic, brownish in colour, ionic and highly soluble in water but insoluble in acetone, chloroform and ethanol. GCMS spectrum of the gum indicated the presence of sucrose, dihex-5- en-2-yl phthalate, stearic acid, 2,6-dimethyl-4-nitrophenol and (E)-hexadec-9-enoic acid. Corrosion inhibition potential of the gum was investigated using weight loss and FTIR methods. Daniella olliverri gum has been found to be a good inhibitor for the corrosion of mild steel in HCl solution. Corrosion inhibition properties of the gum is attributed to the presence of aromatic, suitable functional groups and heteroatoms in its chemical constituents, which facilitated its adsorption. The adsorption of the gum on the surface of the metal was found to be endothermic, spontaneous and supported the mechanism of physical adsorption. The results obtained obeyed the Langmuir adsorption isotherm model.