Corrosion Inhibition of Steel in 1 M Hydrochloric Acid Medium by Chamomile Essential Oils

Abstract

Chamomile oil was tested as corrosion inhibitor of steel in 1 M HCl using electrochemical impedance spectroscopy (EIS), Tafel polarisation methods and weight loss measurements. The inhibition efficiency of chamomile oil was calculated and compared. We note good agreement between these methods. The results obtained revealed that the inhibitor tested reduce differently the kinetic of corrosion process of steel. Its efficiency increases with the concentration and attained 90% at 2 g/l. Effect of temperature on the corrosion behaviour of steel in 1M HCl was also studied in the range 298 K and 328 K. The thermodynamic data of activation are determined. The analysis of chamomile oil, obtained by hydro-distillation, using Gas Chromatography (GC) showed that the major components were were Linoleic acid (54.8 %), Oleic acid (23.5 %), Palmitic acid (10.7 %) and Linolenic acid (6.2).