Abstract: Three polystyrene/graphene oxide (PS/GO) nanocomposites (GO contents 0.1 wt%, 0.3 wt%, and 0.5 wt%) were prepared using home-designed water-assisted-mixing extrusion equipment. Microstructure, rheological behavior, and thermal stability of the nanocomposite samples were investigated. It demonstrated that GO was well exfoliated and dispersed in network structure in PS matrix. This was attributed to the fact that PS chain was easy to intercalate and exfoliate GO layers. PS/GO samples exhibited higher elastic moduli, complex viscosities, and relaxation times at low frequencies as compared with neat PS, which was because of the stronger intermolecular force between well dispersed GO layers in network structure and PS. PS/GO samples exhibited higher thermal stability than neat PS sample, which was due to the GO network in PS matrix and π bond at GO surface.

Key words: water-assisted mixing extrusion, grapheme oxide, polystyrene, microstructure, rheological behavior, thermal stability