Effect of epoxy resin on rheology of polycarbonate/clay nanocomposites

Polycarbonate/clay nanocomposites (PCNs) were prepared by melt intercalation using epoxy resin as a compatibilizer. The intercalated structure of PCNs was investigated using XRD and TEM. The linear and nonlinear dynamic rheological properties of PCNs were measured by the use of a parallel plate rheometer. The results reveal that the presence of epoxy influences rheological behavior of PCNs significantly. Addition of epoxy can improve dispersion of clay, enhancing the low-frequency viscoelastic responses; while high loadings of epoxy lead to a severe degradation of PC matrix, decreasing the high-frequency responses together with the plasticizing effect of excessive epoxy. Both of these two effects result in invalidity of time-temperature superposition. Moreover, all samples show high sensitivity to both the quiescent and large amplitude oscillatory shear (LAOS) deformation, despite enhanced percolation of tactoids due to the compatibilization of epoxy.