Stress growth in dilute solutions of macro-molecules in a non-Newtonian solvent (Q1117768)

The rheological properties of macromolecules in a non-Newtonian solvent at the inception of a steady shear flow are examined within the framework of the kinetic theory of polymeric liquids. The cases of rigid rodlike particles in a second order fluid and of Rouse chains in a Maxwell corotational fluid are considered. For the rigid rods the method of multiple time scales is used to solve the problem under the assumption of small shear rates. For Rouse chains exact solutions are found for arbitrary shear rates. Stress overshoots appear for both types of macromolecules, in contradistinction to the case of a Newtonian solvent where they are predicted only for the rigid rod model.