| Abstract: | Viscoelastic properties of a polystyrene-poly(vinyl methyl ether) blend were measured in oscillatory and steady shear flows near the phase separation temperature. In the one-phase region, the viscoelastic properties are independent of the type of flow and flow geometry, and their shear and frequency dependences are the same as those of homopolymers. When phase separation occurred, a change in viscoelastic properties was observed in all types of flow and flow geometries, and they are different in the different types of flow and/or different flow geometries in the two-phase region. In the shear rate dependence of viscosity of the polymer blend in the two-phase region at quiescence, a plateau region was observed, in which the shear viscosity can be regarded as the zero shear viscosity of the homogenized polymer blend at that temperature. |
