Cross-linkable nitrile functionalized graphene oxide/poly(arylene ether nitrile) nanocomposite films with high mechanical strength and thermal stability

To develop high performance graphene-based nanocomposites, precise interface control and dispersal of graphene in the polymer hosts are challenging due to its strong interlayer cohesive energy and surface inertia. Here, we firstly report an efficient and novel method to functionalize graphene oxide with 4-aminophenoxyphthalonitrile and successfully compound them with poly(arylene ether nitrile)(PEN) to prepare nanocomposite films. Fourier transforms infrared spectra (FTIR), Raman spectra, and atomic force microscopy (AFM) were employed to examine the surface functionalization of the graphene oxide. The resulting PEN nanocomposite, with 0.75 wt% nitrile functionalized graphene oxide (G-CN), revealed an approximate 27% and 68% increase in tensile strength and Young's modulus, respectively, compared to that of neat PEN. The onset thermal degradation temperature (T-d5) and the maximum decomposition temperature (T-d,T-max) of the composite with 0.75 wt % of G-CN were increased by 21 and 25 degrees C compared to those of neat PEN. More importantly, the mechanical and thermal properties of the PEN composite films were further enhanced by the chemical cross-linking reaction of nitriles, which opens a new route to optimize the interface structures and improve the comprehensive performances of graphene-polymer nanocomposites.