Flow Birefringence and Stress. V. Correlation of Recoverable Shear Strains with Other Rheological Properties of Polymer Solutions

Abstract

The correlation of normal stress with the shear stress and flow birefringence of flowing solutions has been extended to include the recoverable shear strain s which can be measured directly by a rotational viscometer in ``recoil.'' This has been shown experimentally with solutions of a high-viscosity nitro-cellulose in n-butyl acetate and a viscous polyisobutylene. These results show that the principal axes of the tensors of stress, strain, and optical anistropy coincide, even when no constant shear modulus (shear compliance) exists.