Subhashini, SRajalakshmi, R2017-02-172017-02-172010https://ir.avinuty.ac.in/handle/avu/1442The 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.