The Corrosion Inhibition of Mild Steel in 0.5m Phosphoric Acid and Crown Cork in Water By Folic Acid

The corrosion inhibition of mild steel in 0.5M H3PO4 solution and crown cork in water by folic acid was investigated using weight loss experiment at different temperature (300C, 400C, 500C). The finding indicates that, folic acid acts as an effective corrosion inhibitor for mild steel in phosphoric acid solution and crown cork in water at 100C. The inhibition process was attributed to the formation of an adsorbed film of inhibitor on the surface of mild steel which protect the metal from corrosion. The inhibition efficiency and surface coverage of mild steel increased with increasing concentration of folic acid, but reduced as temperature increases. The kinetic treatment of the results confirms a first order reaction kinetics with respect to corrosion of mild steel in 0.5M H3PO4 and the crown cork in water in the present of folic acid. The adsorption isotherm model which was determined from the results obtained from weight loss experiment performed on mild steel coupon in phosphoric acid solution fits the Langmuir model. The inhibitive ability of folic acid was attributed to the presence of oxygen, nitrogen and aromatic pyrimidine in its structure.