In the previous paper, the detailed experimental set-up and procedures were described for tubeless siphon or Fano flow, from which the tensile viscosity, ηT, is calculated. Here we investigate the simultaneous effects of temperature and concentration on tensile viscosity. A semi-empirical scaling law has now been established to relate the concentration, c, temperature, T, and deformation rate, ε, by a reduced deformation rate variable to bring all ηT together. Furthermore, ηT has been compared with the steady and dynamic shear data. The onset of high ηT occurs in the vicinity of the onset of non-Newtonian viscosity observed in a simple shear flow experiment. Finally, the asymtotic solution of Hassager’s kinetic theory of a bead-rod model for macromolecular solutions2 has been compared with experimental data. It indicates that ηT depends strongly on the molecular weight, and the higher the molecular weight, the more sensitive the tensile viscosity in terms of ε.
KeywordsDeformation Rate Master Curve Normal Stress Difference Extensional Flow Dilute Polymer Solution
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