USE OF SOLVENT FREE-VOLUME PARAMETERS FROM C-13 RELAXATION TO STUDY POLYMER-SOLVENT DIFFUSION BEHAVIOR

Variable temperature C-13 nuclear magnetic resonance (NMR) spin-lattic e (T-1) relaxation studies were carried out using pure ethylbenzene, t etrahydrofuran, and methanol samples. Single correlation times, determ ined from an isotropic rotational diffusion model, were correlated suc cessfully using the free-volume equation. The solvent free-volume para meters estimated in this study were comparable with those determined f rom viscosity measurements. The solvent free-volume parameters estimat ed in this study were then used to correlate and predict diffusion beh avior of polymer/solvent systems. The results were comparable with tho se using the parameters from viscometry when the Vrentas-Duda free-vol ume diffusion model was used.