Corrosion Inhibition of Mild Steel by Water Soluble Poly (Vinyl Pyrrolidone - Aniline) in IM HCl
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Date
2010
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Abstract
The present work reports the chemical oxidative synthesis of Polyaniline
(PANI) in stable aqueous solution/dispersion form, using poly vinyl
pyrrolidone (PVP) as an efficient steric stabilizer. This Poly (VinylPyrrolidone
- aniline) water soluble composite used as corrosion inhibitor for mild steel in
IM HCl at different concentrations. Weight loss, potenziodynamic
polarization and electrochemical impedance spectroscopy measurements were
employed. Impedance studies indicated an increase in charge transfer
resistance and decrease in double layer capacitance with increase in inhibitor
concentration. Potenziodynamic polarization study implies that the inhibitor
acts as mixed type inhibitor. Maximum inhibition efficiency was witnessed
with 0.2 % percentage of PVPA. The adsorption of the compounds on mild
steel surface was found to obey Langmuir’s and 'I'emkin’s adsorption
isotherm. The values of activation energy, free energy of adsorption, heat of
adsorption, enthalpy of activation, entropy of activation were also calculated
to elaborate the mechanism of corrosion inhibition.