COMPLETE FLOW CURVE OF VISCOELASTIC SYSTEMS

By previous thermodynamical calculation the deviations from Newtonian behavior in the flow of high polymers were characterized as visco elastic effects. Besides this classification in Newtonian and superposing parabolic flow rheological experience discloses the existence of an additional second Newtonian flow range under high shear stress. - With respect to extensive or finally complete stretching of the macromolecule under high shear stress the transition from the parabolic to a second Newtonian flow range was derived by statistical thermodynamics. In this way a further rheological method became accessible for absolute determination of high polymer average molecular weights as well as an estimating criterion for the melt flow behavior in high stress injection moulding.