Poly(o-toluidine)/nano ZnO composite was prepared by in situ polymerization of o-toluidine monomer
in the presence of nano ZnO particles. Fourier transformation infrared spectroscopy (FT-IR), UV–visible
spectroscopy (UV–vis), X-ray diffraction (XRD), Scanning electron microscopy (SEM) and Thermogravi-
metric analysis (TGA) were used to characterize the composition and the structure of the composite. Poly
(o-toluidine)/nano ZnO composite was mixed with epoxy resin through a solution blending method and
the poly(o-toluidine)/nano ZnO/epoxy composite coating was coated onto the surface of steel sample,
and its corrosion resistance properties were studied by potentiodynamic polarization, electrochemical
impendence spectroscopy measurements and immersion test in 3.5% NaCl solution and also compared
with that of poly(o-toluidine)/epoxy composite coating, pure epoxy coating and uncoated steel sample.
The results showed that the composite coating containing poly(o-toluidine)/nano ZnO composite has
higher corrosion resistance than that of poly(o-toluidine). The enhancement of corrosion protection
ability of poly(o-toluidine)/nano ZnO composite containing coating may be due to the formation of more
uniformly passive layer on steel surface and the addition of nano ZnO particles, which increases the
 .tortuosity of the diffusion pathway of corrosive substances.