Development of amine functionalized graphene oxide/fluorinated polyurethane topcoat with integrated anti-corrosion, anti-aging, and anti-bacterial performance

The amine functionalized graphene oxide (AFGO) was prepared by introducing highly reactive chloride groups on the surface of graphene oxide (GO) via its reaction with 2-amino-4,6-dichloropyrimidine (ADP). The obtained AFGO was compounded with fluorinated polyurethane (FPU) through ball milling and dispersion to fabricate AFGO/FPU nanocomposite coatings. The structure and microscopic morphology of AFGO were characterized by Fourier transform infrared spectrometer (FTIR), ultraviolet-visible spectrometer (UV–vis), X-ray powder diffraction (XRD), X-ray photoelectron spectrometer (XPS), and transmission electron microscopy (TEM). The tensile strength, morphology, and thermal stability of the AFGO/FPU nanocomposite coating before and after aging were also systematically characterized. The results showed that the coating surface remained smooth after the aging experiments, and no significant pulverization occurred. The corrosion resistance of the nanocomposite layer with the incorporation of AFGO filler was characterized by electrochemical impedance spectroscopy (EIS) and salt spray test. The results showed that the low-frequency impedance (|Z|0.01Hz) of AFGO/FPU coating was 1.562 × 109 Ω·cm2 after 900 h salt spray test, which was still two orders of magnitude higher than that of GO/FPU nanocomposite coating. The antibacterial experiments showed that the AFGO/FPU nanocomposite coating showed bacterial inhibition as high as 98.7 %, exhibiting better antibacterial properties than the GO/FPU nanocomposite coating.