Berlin 2008 – wissenschaftliches Programm
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CPP: Fachverband Chemische Physik und Polymerphysik
CPP 29: Polymerphysics I
CPP 29.4: Vortrag
Donnerstag, 28. Februar 2008, 10:15–10:30, C 130
Free volume in two untreated, presure-densified, and CO2 gas exposed polymers — Günter Dlubek1, Jürgen Pionteck2, •Muhammad Qasim Shaikh3,4, Liane Häußler2, Stefan Thränert3, Essmat Sayd Hassan3, and Reinhard Krause-Rehberg3 — 1ITA Institut für Innovative Technologien, Köthen/Halle, Wiesenring 4, D-06120 Lieskau (Halle/S.), Germany — 2Leibniz-Institut für Polymerforschung Dresden e.V., Hohe Strasse 6, D-01069 Dresden, Germany — 3Martin-Luther-Universität Halle-Wittenberg, Fachbereich Physik, D-06099 Halle/S., Germany — 4Technische Fakultät, Lehrstuhl für Materialverbunde, Christian-Albrecht Universität, Kaiser Str.2, D-24143, Kiel, Germany
Changes in the microstructure of the free volume and its temperature dependence in ethylene-norbornene copolymer and bisphenol-A polycarbonate due to densification under pressure and swelling with CO2 gas have been examined using positron annihilation lifetime spectroscopy (PALS) and were compared with pressure-volume-temperature (PVT) experiments from Dresden. From the PALS spectra analyzed with the new routine LT9.0 the size distribution of subnanometre holes and its mean and mean dispersion were calculated. Above Tg, the dispersion mirrors the thermal fluctuations in the free volume. PALS data show that the mean hole size and its dispersion in the glassy state is decreased due to densification and increased due to swelling.