Estimation of viscosities of mixed polymer solutions

Abstract

SynopsisA semiempirical model for estimation of viscosities of concentrated polymer solutions' can be applied to mixtures of polymers in a common solvent. The data required for estimation of mixture viscosity are: solvent viscosity, polymer molecular weight, density, concentration, and intrinsic viscosity in the particular solvent. Calculated and experimental viscosities agree to within a few per cent for the relatively nonpolar systems for which comparative data are available. The model does not appear to be adequate for mixtures in which there are extensive hydrogen-bonding interactions.Results of the new model are equivalent to those of an empirical equation2 reported to be effective for fairly concentrated binary polymer mixtures.Specific interactions between polymeric solutes can be conveniently assessed by comparing measured mixture viscosity to that calculated from the model presented. It is not clear, however, that such assessments have any fundamental significance, since the interactions which are calculated depend on the assumptions inherent in the estimation of the "ideal'' mixture viscosity. The same reservations apply to other models which have been proposed for this purpose.

Comparison of two low‐hazard organic solvents as individual and cosolvents for the fabrication of polysulfone membranes

“…In this study, viscosity was used as the parameter to demonstrate the dissolution process of the PSf/solvent system since viscosity is related to water transport during phase inversion. The viscosity of polymeric dope solution reflects hydrogen bonds in between the solvent and polymer . High viscosities are undesirable since they retard the transport of water during phase inversion and ultimately form dense outer layers.…”

Scaling Equation for Viscosity of Polymer Mixtures in Solutions with Application to Diffusion of Molecular Probes

“…Until now, various ways of predicting viscosity of liquid mixtures have been proposed, mainly for industrial purposes (for a review and comparison see ref ), which however provide no insight into the underlying physics. Models developed specifically for mixtures containing polymers − are rather scarce and require a number of empirical parameters yet do not consider the mesoscopic structure of the complex liquid. This also means that there are no methods available that would allow for quantification and prediction of diffusion coefficients of (macro)­molecular probes in systems containing more than a single type of crowding agent.…”

Investigation on polyacrylonitrile/cellulose acetate blends

“…A ternary system contains a solvent (component 1) and two polymers (component 2 and 3), which can be set in this equation: 11,12 (1) b m C 2 = b 22 C 2 2 + b 33 C 3 2 + 2b 23 C 2 C 3 Krigbaum and Wall suggested 13 that information about the interaction between two polymers should be obtained from Δb expressed as:…”