Solvent Diffusion Coefficient Concentration Dependence in Polymer Solutions
Abstract
Self-diffusion coefficients of several different solvents in polystyrene, as well as, methyl methacrylate in poly(methyl methacrylate) have been determined at polymer concentrations from 0 to 50 wt% at 25 deg C. The solvents used for the polystyrene solutions were toluene, ethylbenzene, cumene, t-butyl acetate, chloroform, and methyl ethyl ketone. The diffusion data was used to evaluate several theories for the concentration dependence of the solvent diffusion coefficients, and in most cases the reduced diffusion coefficients, of solvents in polymer-solvent systems. In addition to the experimental data presented here, literature data for several systems were also used to test the models. The theories evaluated were based on widely different concepts including electrical conductivity, tortuosity, kinetic theory, and free-volume. The results indicate that the kinetic theory and free-volume approaches fit the data most consistently, with the kinetic theory approach preferred at lower polymer concentrations and the free-volume approach favored at higher polymer concentrations. Self diffusion, Kinetic theory, Free volume, Solvents, Polymers.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 15, 1994
- Accession Number
- ADA277023
Entities
People
- Frank D. Blum
- J. M. Macelroy
- R. A. Waggoner