L. An, A. Hinrichs, R. Horst, C. Krause and B. A. Wolf

"Shear Induced Mixing/Demixing: Blends of Homopolymers, of Homopolymers plus Copolymers, and Blends in Solution;

**Abstract:** Shear may shift the phase boundary towards the homogeneous
state (shear induced mixing, SIM), or in the opposite direction (shear induced
demixing, SID). SIM is the typical behavior of mixtures of components of low
molar mass and polymer solutions, SID can be observed with solutions of high
molar mass polymers and polymer blends at higher shear rates. The typical sequence
with increasing shear rate is SIM, then occurrence of an isolated additional
immiscible area (SID), melting of this island into the main miscibility gap,
and finally SIM again. A three phase line originates and ends in two critical
end points. Raising pressure increases the shear effects. For copolymer containing
systems SID is sometimes observed at very low shear rates, preceding the just
mentioned sequence of shear influences.

preprint number: 204a