Sorption of low molecular weight solutes in glassy polymers is known to often result in swelling of the polymer phase. The swollen polymer may on occasion crystallize. One thus has a phenomenon where three different rate processes take place simultaneously and are coupled with each other: diffusion, swelling and crystallization. Correspondingly, there are as many as four time scales: the one for diffusion, the swelling time, the crystallization time, and the relaxation time for the mass flux; the last is shown to be crucial to the possible development of discontinuities and quasi-discontinuities in the state of the polymer. A model has been developed to take into account all these phenomena, and experimental data are successfully compared with the model predictions. Specific numerical techniques have been developed to deal with the resulting quasi-linear hyperbolic equations.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering