Effect of Nano-graphene on the Mechanical and Rheological Properties of Nanocomposite based on Polystyrene Using SBS as Compatibilizer

In the this work, the effect of nano-graphene, as a platelet reinforcement, on the mechanical (tensile and impact strength) and rheological properties of general purpose polystyrene was investigated. Styrene-butadiene-styrene (SBS), was used as a compatibilizer and its effect on the improvment of nano-graphene distribution was also studied. The range of studied concentration were 0.01, 0.02 and 0.05 wt.% for graphene and 5 and 10 wt.% for SBS. The samples were prepared by melt blending method in a corotating twin screw extruder. The morphology of the samples was characterized through transmission electron microscopy (TEM) and X-ray diffraction (XRD). Further more, the mechanical properties of the all samples were analysied by tensile and impact strength tests. The rheological properties was investigated under small amplitude oscillatory shear (SAOS). The results of XRD and TEM showed a better dispersion and distribution of nano-graphene for the compositions having SBS. For all the nanocomposites with SBS the brittle failure disappeared and cold drawing area increased. The highest elongation at break and impact strength was obtained for the composition with 5 wt.% SBS and 0.05 wt.% graphene. Also, for this system the impact strength improved more than 6 times compared to pure PS. While mechanical properties improved even with low amount of graphene in the presence of SBS, the rheological measurement showed that complex viscosity reduced in these compositions which is a favorable phenomena from processing point of view.