An equation suggested by Fedors for application to intrinsic viscosity determination of dilute to moderately concentrated solutions is re-examined taking into account polymer swelling behaviour and polymer-solvent interactions. For a given polymer-solvent system, the observed variation of the constant of the equation (defined as the maximum volume fraction to which polymer particles can pack), q~m, and its estimated values beyond its theoretical limit of unity are the main difficulties in its application. These problems are solved by a suggested modification to the equation, and ~b m is shown to be less than or equal to unity and constant for many polymer-solvent systems. This modification facilitates the use of the Fedors equation for dilute to concentrated polymer solutions for determining the intrinsic viscosity at a single polymer concentration.
Посилання на статтю:
Viscosity of dilute to moderately concentrated polymer solutions / M. V. S. Rao // Polymer. – 1993. – Vol 34. – P. 592-596.