Preparation, Characterization and Tribological Performance of Polyurethane (PU) Coatings Filled with Graphene Oxide (GO)

Abstract

The polyurethane coatings containing different concentration of graphene oxide were prepared. Their physicochemical properties were characterized by XRD and SEM. The tribological behaviors were also investigated by ring-on-block tests. Results revealed that the TDI adsorb on the surface of GO through reaction with O-H. The COF were extremely sensitive to the GO concentration of PU coatings filled. The COF of pure PU coating was 0.185, whereas it is sharply decreased when 1.0 wt% GO was added. Smaller COF was obtained as the GO concentration increase and to minimize when GO concentration is 2.0 wt%. Friction reduced mechanism of GO was further investigated. Two reasons were responsible for this phenomenon. The one was that the GO itself possessed the capacity of anti-wear and friction reduction. Another one was the GO dispersed in the PU coatings could increase the strength of the coatings by the mean, which was similar to dispersion strengthening.