Excluded Volume Effect on the Intrinsic Viscosity of Chain Polymers

Abstract

The excluded volume effect on intrinsic viscosity of chain polymers is calculated by assuming the equivalent ellipsoid-polymer model suggested in the previous paper with additional assumptions that this polymer model is rigid and impenetrable for solvent flow. The intrinsic viscosity [η] depends on the expansion coefficient α of excluded volume effect through the relation: [η]∝α^2.45 for wide range of α.
The ellipsoidal polymer model used in the calculations is examined by the Monte Carlo calculations. Thus the calculations find that the mean axial ratio of ellipsoid increases almost linearly with the radius of gyration, and its most probable value for random coil chain is about 2.5.
By combining the present result with the previous theory, two empirical relations between intrinsic viscosity and molecular weight of polymer are obtained, and their comparisons with the experimental results on several polystyrene solutions show the qualitative coincidences.