Rheological Properties of Polystyrene/Polypropylene (PS/PP) Blends: The Effects of Various Compatibilizers

Abstract

Studies on rheological properties of polystyrene/polypropylene (PS/PP) blends with and without the addition of various compatibilizers were carried out. PS/PP blends of 20/80, 50/50 and 80/20 (wt%) were prepared through melt blending in a single screw extruder at a screw speed of 40 rpm and temperature of 200 oC. The rheologycal properties were evaluated by melt flow indexer machine with the temperature of 200 oC. Four types of compatibilizers viz. polystyrene-block-poly (ethylene-butylene)-block-polystyrene (SEBS), surlyn, ethylene vinyl acetate (EVA) and sodium salt hydrate of 4 styrenesulfonic acid (ssh-4-ssh) were used in this study. The concentration of the compatibilizer is 7.5wt%.Results show for uncompatibilized blend, all blend compositions exhibit a reduction in melt viscosity, but the incorporation of EVA, surlyn and SEBS produced more resistance system to flow and increased the melt viscosity. However, in the presence of ssh-4-ssa a reduction in melt viscosity was observed, indicating easier for blend to flow.