Dynamic Investigations of Polymeric Systems in Viscoelastic State with Polymer Concentration Above Critical

The dynamic deformation of polymeric systems (spinning solutions of polymers) with a polymer concentration above the critical value, characterized by an unstable deformation regime, was investigated. The unified theory of deformation of polymeric systems in a viscoelastic state, by means of which it is possible to undertake a rheological analysis of the viscoelastic characteristics of polymeric systems from two measurement points over a wide range of variation of velocity gradient, was used for the investigation. It was shown that the intersection of the classical loss modulus and elasticity modulus curves is due to transition of the polymeric system to an enforced elastic state with the appearance of an effect from negative complex viscosity and its negative elastic component. Good agreement is observed during comparison of the data of unified deformation theory and experimental data for the stable deformation region.