A comprehensive study on crude methanolic extract of Artemisia pallens (Asteraceae) and its active component as effective corrosion inhibitors of mild steel in acid solution

Corrosion inhibition effects of crude methanolic extract of Artemisia pallens on mild steel in 1 mol l(-1) HCl were studied by weight loss and electrochemical technique. Arbutin. an active principle from A. pallens and the crude methanolic extract exhibited inhibition efficiency of 93% and 98% in 400 mg l(-1) concentration at 30 degrees C respectively. The results indicated that arbutin in acidic medium acted as good anti-corrosive agent synergistically with its hydrolyzed products hydroquinone and D-glucose. Adsorption of both the inhibitors on mild steel surface conformed to the Langmuir isotherm with standard adsorption free energy of -33.07 kJ mol(-1) for arbutin. (c) 2012 Elsevier Ltd. All rights reserved.