Free volume theory is used to correlate and predict self-diffusion coefficients for several polymethacrylate monomer systems at high solvent concentrations. The free volume theory has traditionally been used to correlate and predict diffusional behavior in polymer systems at low solvent concentrations. This study is one of the few to test and evaluate the theory at high solvent concentrations. The data were collected at 25°C and 40°C using pulse gradient NMR at solvent weight fractions ranging from 0.1 to 1.0. In some cases, the free-volume theory is used as a correlating technique and in others where the free-volume characteristics of the polymer and solvent are available; it is used to predict the diffusional behavior. Contrary to conventional wisdom regarding the range of applicability of free-volume theories, these results show that diffusional behavior in dilute polymer-solvent systems is consistent with free-volume concepts.

*School of Chemistry, Sydney University, Sydney, Australia