Facile Preparation of Polyaniline Nanoparticles and Their Dispersion for Waterborne Anticorrosion Coatings

Waterborne conductive polyaniline/polyvinylpyrrolidone (PANI/PVP) nanoparticles were prepared using as PVP stabilizer and phosphoric acid as dopant via dispersion polymerization. The resulting PANI/PVP nanoparticles were characterized by TEM, FTIR, UV-vis spectra, cyclic voltammetry and XPS, which showed regular spherical morphology with uniform diameters in the range of 60-80 nm and good electroactivity. The addition of PANI/PVP nanoparticles significantly improved the anticorrosion properties of waterborne epoxy coating, based on polarization curves and EIS measurements performed in 3.5% NaCl solution. Especially, the epoxy coating containing 1.0 wt% PANI/PVP exhibited best corrosion protective effect. The remarkably enhanced anticorrosion performance could be attributed to the redox catalytic properties of PANI/PVP nanoparticles and the inhibitory effect of doping anions.