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DY: Dynamik und Statistische Physik

DY 17: POSTER I

DY 17.19: Poster

Montag, 27. März 2000, 15:00–18:00, D

Gas transport in glassy polymers. — •Pekarski P., Brion H.-G., and Kirchheim R. — Institut fuer Materialphysik, Hospitalstr. 3-7, Goettingen

We report about measurements of gas diffusion in substituted polycarbonates and polystirol. The activation energy of diffusion depends on the size and the shape of gas molecules as well as on solute concentration. The measurements of diffusivities in extended temperature interval show a difference in apparent activation energy below and above the polymer glass transition. We interpret these experimental observations within the framework of the recently developed Site Distribution model. Finally we compare activation energies obtained by the pressure decay technique with the activation energies of single diffusive jumps obtained by means of mechanical spectroscopy.