Rheological and extrusion behavior of intercalated high-impact polystyrene/organomontmorillonite nanocomposites

High-impact polystyrene (HIPS)/organomontmorillonite (Org-MMT) nanocomposites were prepared by melt processing using a twin-screw extruder. Intercalation of the Org-MMT in the HIPS matrix was achieved as revealed by both X-ray diffraction and transmission electron microscopy. Great attention was focused on the rheological and extrusion behavior of HIPS/Org-MMT nanocomposites via a capillary theometer owing to the resemblance of its conditions of operation to those prevailing during the practical fabrication process of materials. The rheological data of the nanocomposites exhibited power-law relationship of flow and sharper shear thinning compared to the polymer matrix. With increasing Org-MMT loadings, the flow behavior index, n' decreased at a constant temperature and shear rate whereas the apparent shear viscosity, eta(a) increased slightly. The dependence of eta(a) on temperature was in accordance with Arrhenius-Eyring expression. The addition of Org-MMT resulted in a decline in extrusion swell and melt elasticity of the nanocomposites. (c) 2005 Elsevier Ltd. All rights reserved.