Extensive oscillatory flow birefringence and dynamic viscoelastic measurements on a variety of polymer-solvent systems indicate that the solvent contributions to the measured solution properties are not given by the neat solvent birefringence or viscosity, respectively, by contrast with the predictions of chain dynamics theory. Rather, the high frequency limiting plateaus observed in the loss components of both the dynamic birefringence and dynamic viscosity, designated S′∞ and η′∞, respectively, represent the appropriate solvent contributions. Measurements of solvent rotational and translational friction in some of the same polymer-solvent systems provide direct support for the postulate that the values of S′∞ and η′∞ reflect predominantly polymer-induced modifications to the dynamics of the solvent surrounding the chains.
Bibliographical noteFunding Information:
This work was supported by the National Science Foundation through grants DMR-7925020, DMR-830207, DMR-8800641 to J.L.S. and DMR-8319291 and DMR-8715391 to T.P.L.