Multiwall carbon nanotubes-reinforced epoxy hybrid coatings with high electrical conductivity and corrosion resistance prepared via electrostatic spraying

The hybrid coating of multiwall carbon nanotubes (MWCNTs) reinforced epoxy resin was deposited onto the carbon steel by electrostatic spraying. Its microstructure and performance was investigated by FTIR, SEM, TG, four-point probe, electrochemical impedance spectroscopy and electrochemical potentiodynamic polarization curve measurement. The hybrid coatings containing MWCNTs had a similar thermal stability, and exhibited the excellent adhesion to the substrate. The electrical conductivity of the hybrid coating was enhanced by the addition of MWCNTs into epoxy resin matrix. With the increase of MWCNTs content, its electrical resistivity was decreased. It was decreased to 7.6 × 10−2 Ω m by the addition of 2 wt% of MWCNTs. The corrosion resistance of the hybrid coating was higher than that of the bare carbon steel in the saline environment. It was found that the MWCNTs content had a great effect on the corrosion resistance of the hybrid coating. When the MWCNTs content was 2 wt%, the hybrid coating has the highest anticorrosion and good conductivity, which potentially employed for bare carbon steel against the corrosive environment.