Influence of Composition and Phase Morphology on Rheological Properties of Polypropylene/Poly(ethylene-co-octene) Blends

In this article, the phase morphology and rheological properties of polypropylene (PP)/poly(ethylene-co-octene) (POE) blends with a droplet-matrix microstructure were studied by scanning electron microscopy and rheological experiments. The data were analyzed to yield the variations of rheological behavior with blend composition and insight into the microstructure of PP/POE blends. The Palierne's emulsion type model was used to extract information on rheological properties, and the interfacial tensions between the PP and POE were determined by fitting the experimental data with this model. The results indicated that the interfacial tensions were shown to depend on blend composition and temperature. Rheological properties of PP/POE blends were investigated in a systemic way with varying shear histories. The results showed that shear history had an important effect on the rheological properties of the blends due to the dispersed phase (POE) domains refined with increasing preshear rate and preshear time. POLYM. COMPOS., 31:105-113, 2010. (C) 2009 Society of Plastics Engineers