Graphene Oxide-Loaded Zinc Phosphate as an Anticorrosive Reinforcement in Waterborne Polyurethane Resin

Graphene oxide zinc phosphate (GO-ZP) composites were synthesized by a one-step ultrasonic wave- assisted method and then incorporated into waterborne polyurethane as the anticorrosive reinforcement to produce graphene oxide zinc phosphate/polyurethane (GO-ZP/PU) composites. The GO-ZP composites were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The anticorrosive properties of the GO-ZP-reinforced PU composite coatings were characterized by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS). The correlations among the mass ratio of GO to Zn3(PO4)2, the concentration of GO- ZP added to the waterborne polyurethane (WPU) and the anticorrosive properties of the composites were investigated. The results showed that excellent anticorrosive properties were achieved for the GO-ZP/PU composite with the 0.5 wt% GO-ZP (3:1) coating, which had a corrosion current density (icorr) of only 4.41×10-7 A/cm2 and a charge transfer resistance (Rct) of 1.104 ×101 Q cm2.