Influence of stochastic environments of Gaussian chains on dynamic shear and bulk properties

摘要

A theory of dynamic bulk and shear viscosity in polymer systems is presented. To overcome the neglect due to the preaveraged hydrodynamic interaction in the theory of dynamic viscoelastic properties of polymers, a perturbation term, which includes the influence of external environments coupled to the velocity field, was introduced in the dynamic equation. The influence of this additional perturbation term to both dynamic bulk and shear properties was studied. This nonthermodynamic contribution modifies the Rouse spectrum. It was shown that the relaxation time spectrum is the same for the dynamic bulk eegr;Vand shear viscosity eegr;S, whereas the ratio between the both quantities was found to exceed the value eegr;V/eegr;S=2/3 for pure viscous drag. The theoretical results are compared with experimental data.