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CPP: Chemische Physik und Polymerphysik
CPP 18: Poster: Polymer Blends, Heterogeneous Systems, Colloids and Nanoparticles, Interfaces, Polyelectrolytes
CPP 18.7: Poster
Mittwoch, 4. April 2001, 12:30–15:00, AT1
Dielectric spectroscopy on low-density polyethylene filled with titanium dioxide — •Frübing Peter1, Blischke Dörte1, Gerhard-Multhaupt Reimund1, and Khalil M. Salah2 — 1Applied Condensed-Matter Physics, Department of Physics, University of Potsdam, Am Neuen Palais 10, 14469 Potsdam, Germany — 2Department of Electrical and Electronics Engineering, College of Engineering, Sultan Qaboos University, Muscat, Sultanate of Oman
Low-density polyethylene (LDPE) filled with a small amount (1 to 10 wt%) of titanium-dioxide powder proves to be very suitable for studying the molecular motion of polyethylene with dielectric spectroscopy. The titanium-dioxide particles act as oxidizing agents inducing a small concentration of polar carbonyl groups which do not alter molecular motion, but couple it to the alternating electric field.
The frequency and temperature dependences of molecular-motion processes in LDPE are determined from isochronal and isothermal loss plots. In particular, the temperature dependence of the β process connected with the glass-rubber transition in polyethylene obeys the Vogel-Fulcher-Tammann-Hesse law, which indicates co-operative behaviour. The dielectrically determined glass-transition temperatures center around 255 K. Reasonable agreement with the value obtained from differential-scanning calorimetry is found.