Effect of Methanol Extract of Chamaerops Humilis L. leaves (MECHLL) on the Protection Performance of Oxide Film Formed on Reinforcement Steel Surface in Concrete Simulated Pore Solution

摘要

The methanol extract of Chamaerops humilis L. leaves (MECHLL) obtained by the soxhlet techniquewas analyzed by GC/MS and FT-IR spectroscopy. The extract is constituted by Lucenin 2 (42%),Dasycarpidan-1-methanol, acetate (ester) (11%), 1, 3-D-5-hexan-2-one-2, 4-dinitrophenylhydrazone(10%) and 9-Hexadecenoic acid (8%) as the most abundant compounds. The effect of the extract onthe protective property of the oxide film formed on the reinforcement steel surface in alkaline solution(pH > 13) was investigated by electrochemical techniques. Inhibition efficiency of 42% was obtainedwith 0,5g/L of inhibitor at 25C.The Nyquist plots showed that the variation of immersion timeincreases the polarization resistance and associated capacitance. The addition of the inhibitor caneffectively decrease the reinforcement steel corrosion, enhance the stability of the film formed inalkaline solution and lead to the formation of a more compact protective layer on the surface. Action ofthe MECHLL obeys to the Langmuir adsorption isotherm. Finally the inhibition efficiency of theextract was discussed in terms of adsorption and protective film formation.