Abstract:
The study of mild steel corrosion phenomena has become important particularly in acidic
media because of the increased industrial applications of acid solutions. Green organic
compounds serve as effective inhibitors for corrosion and they are naturally synthesized
chemical compounds that are environmentally acceptable, inexpensive, readily available
and renewable source of materials. Inhibition effect of water and methanol extracts of
raw Teak leaves and the effect of temperature on the corrosion of mild steel in lM HC1
medium were studied using weight loss measurements. It was found that water extract
possess better inhibition effect than methanol extract of Teak leaves. The adsorption
of the inhibitor on the surface of mild steel obeys the Langmuir adsorption isotherm.
According to the estimated adsorption equilibrium constant, Kads and standard Gibbs free
energy change, AG°ads of the adsorption process, adsorption of the Teak leave extract on
mild steel surface mainly take place by chemisorption. The behavior of the inhibitor was
investigated using potentiodynamic polarization techniques and it was revealed that the
extracts contain mixed type corrosion inhibitors.
