Preparation of Poly(o-toluidine)/Nano Zirconium Dioxide (ZrO 2 )/Epoxy Composite Coating and Its Corrosion Resistance

Conducting polymers represent a promising application prospect in the field of metal corrosion control. In this investigation, poly(o-toluidine) (POT)/nano zirco- nium dioxide (ZrO2) composite were prepared by in situ polymerization of o-toluidine monomer in the presence of nano ZrO2 particles. Fourier transformation infrared spec- troscopy, UV-visible spectroscopy, X-ray diffraction and Scanning electron microscopy were used to characterize the composition and the structure of the composite. POT/nano ZrO2 composite was mixed with epoxy resin (EP) through a solution blending method and the three components POT/ nano ZrO2/epoxy composite coating was coated onto the surface of steel coupon, and its corrosion protective effi- ciency was studied by electrochemical measurements and immersion test in 3.5 % NaCl solution as corrosion envi- ronment and also compared with that of POT/epoxy com- posite coated steel, polyaniline (PANI)/epoxy composite coated steel and pure epoxy coated steel. According to the results, POT/nano ZrO2/epoxy composite coated steel has got higher corrosion resistance than that of POT/epoxy composite coated steel and PANI/epoxy composite coated steel. It was found that POT powders dispersed in the epoxy and polyamide system improved the barrier and electro- chemical protection properties of epoxy coating and the addition of nano ZrO2 particles increased the tortuosity of the diffusion pathway of corrosion substances.