Accession Number:

ADA277023

Title:

Solvent Diffusion Coefficient Concentration Dependence in Polymer Solutions

Descriptive Note:

Technical rept. 1 Apr 1993-15 Feb 1994

Corporate Author:

MISSOURI UNIV-ROLLA DEPT OF CHEMISTRY

Report Date:

1994-02-15

Pagination or Media Count:

36.0

Abstract:

Self-diffusion coefficients of several different solvents in polystyrene, as well as, methyl methacrylate in polymethyl 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.

Subject Categories:

  • Organic Chemistry
  • Physical Chemistry
  • Polymer Chemistry
  • Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE