This study is concerned with the effect of compatibilizer on the mechanical, rheological properties and morphology of PP/PS blends. Those properties were investigated by using a differential scanning calorimeter (DSC), a scanning electron microscpe, a tensile tester, a capillary viscometer and the Physica rheometer. PP/PS blends with compatiblizer was prepared by melt blending with Brabender (twin screw extruder).
The PP/PS blends showed the morphology of finer dispersion and smaller sizes of dispersed phases with the addition of the compatibilizer. They also showed the improved mechnical properties of the PP/PS blend by the addition of 1 wt. % compatibilizer concentration. A major reduction in the disperse phase size took place at 1 wt. % of the compatibilizer cocentration.
Several factors influencing on the final morphology of the blends are viscosity ratio, interfacial tension(compatibilizer), shear rate/shear stress, viscoelasticity and mixing condition.
The size of disperse phases in the blend, which has the viscosity ratio($\eta_d$/$\eta_m$) larger than 1, increases with the viscosity ratio while disperse phase size, which has the viscosity ratio($\eta_d$/$\eta_m$) smaller than 1, decreases. The size of disperse phases in the blend increase with the shear rate. These results correspond to other research with the different blend systems.
The logitudinal morphology varied from thin thread structure to ellisoidal structure when the viscosity ratio from 0.36 to 2.64. The logitudinal morphology showed the improved adhesion of the interface with the addition of the compatibilizer. Our study showed that the viscosity ratio has more effect than the shear rate.
