NON-NEWTONIAN FLOW OF SOLUTIONS OF HIGH MOLECULAR WEIGHT POLYMER IN EXTREMELY VISCOUS SOLVENTS
Abstract
Recent theoretical work has predicted that the intrinsic viscosity of very long chain polymers in viscous solvents should increase with increasing shear gradient. Highly viscous solvents are required to develop sufficient shearing forces to overcome the inner viscosity (rigidity) of the polymer coil. This report concerns experimental work directed toward examination of the theory. Two polyphenylene oxide fractions, 1290,000 and 345,000 molecular weight, in pyralene and two polyisobutylene fractions, 600,000 and 1850,000 molecular weight, in paraffin oil, were measured in precision equipment which covered five velocity gradient ranges. The maximum shear stresses for pure water, paraffin oil and pyralene are 640, 2600 and 3900 dynes/sq cm. In these solvents no increase in intrinsic viscosity, as predicted, was observed. Although more information is required before the theory can be fully evaluated, it is suggested that the proposed treatment of gradient dependence does not take into account sufficiently the inner viscosity of the macromolecular coil and anisotropic hydrodynamic interaction.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1965
- Accession Number
- AD0624712
Entities
People
- Ragner Stromberg
Organizations
- Uppsala University