UV-Curable Functionalized Graphene Oxide/Polyurethane Acrylate Nanocomposite Coatings with Enhanced Thermal Stability and Mechanical Properties

Functionalized graphene oxide (FGO) was synthesized and subsequently incorporated into polyurethane acrylate (PUA) by UV curing technology. The structural and morphological features of FGO/PUA nanocomposite coatings were characterized by FTIR, XRD, and TEM. The results showed that FGO sheets were uniformly dispersed into the PUA matrix and formed the strong interfacial adhesion with PUA owing to the formation of the cross-linking networks between FGO and PUA after UV curing. The incorporation of FGO effectively enhanced the thermal stability and mechanical properties of host polymer. The initial degradation temperature of the PUA composite with 1.0 wt % FGO was increased to 316 °C from 299 °C for neat PUA. Meanwhile, the storage modulus and tensile strength of the PUA composite with 1.0 wt % FGO were also improved by 37% and 73%, respectively, compared with those of neat PUA. The slight increase in glass transition temperature (T g) of the composites was observed upon the incorporation of FGO. By contrast, untreated GO/PUA nanocomposites exhibited relatively low thermal stability and poor mechanical properties than its modified-GO counterpart. The covalent functionalization of graphene oxide presented herein will provide a feasible and effective approach to obtain high-performance UV-curing nanocomposite coatings.