Theory of dilute polymer solutions in viscoelastic fluid with a single relaxation time

Rheological equations of state of dilute polymer solutions in viscoelastic fluid with one relaxation time are derived by applying a structural approach. The system under consideration is simulated by the superposition of two interpenetrating interacting conitua. The hydrodynamic behaviour of single polymer chains is simulated using the subchain model representing a linear sequence of frictional centres, spherical Brownian particles chain-bonded by means of elastic forces. The oscillatory shearing flow of the solution is studied on the basis of the equations derived. The expressions for the complex viscosity and relaxation times are determined. It is shown that the availability of polymer additions brings about a strong smearing of the relaxation spectrum of the carrying medium.