Synthesis and characterization of polypyrrole composites for corrosion protection of steel

Corrosion protection performance of epoxy polyamide coatings containing polypyrrole (PPy) composites for steel has been studied. PPy and its composites have been synthesized chemically using potassium permanganate and potassium per sulfate as oxidants. The PPy has been characterized by four probe method for conductivity, atomic absorption spectroscopy for elemental analysis, and Fourier transform infrared spectra for proving the incorporation of dopant in this polymers. The X‐ray diffraction (XRD) study has revealed the presence of manganese dioxide in the polymer. The elemental analysis and the thermo gravimetric analysis measurements showed that the presence of manganese dioxide in the polymer is about 75%. The thermal stability of deprotonated polymer has improved. Electrochemical impedance spectroscopic analysis indicated that the epoxy polyamide/PPy‐MnO₂ coating showed the maximum resistance value of 2.196 × 10⁷ Ω cm² after 30 days immersion in 3% sodium chloride solution. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010