The Effect of Acanthus montanus Leaves Extract on Corrosion of Aluminium in Hydrochloric Acid Medium

The inhibitive effect of Acanthus montanus leaves extract on aluminium corrosion in hydrochloric acid solutions was studied using weight loss technique. It was found that the leaves extract retards the acid induced corrosion of aluminium. Inhibition efficiency was observed to increase with increase in inhibitor concentration but decreased with rise in temperature. Thermodynamic studies revealed that the corrosion inhibition may be due to the spontaneous physical adsorption of the extract constituents on aluminium surface. Adsorption was found to obey Temkin isotherm. A first–order mechanism has been deduced from the results at all temperatures studied.