Berlin 2012 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe
CPP: Fachverband Chemische Physik und Polymerphysik
CPP 14: Poster: Glasses I (jointly with DY)
CPP 14.6: Poster
Dienstag, 27. März 2012, 18:15–20:15, Poster A
High-frequency laser modulated AC-chip calorimetry investigations of glass transition of polymers — •Yeong Zen Chua, Evgeni Shoifet, Gunnar Schulz, and Christoph Schick — Universität Rostock, Institut für Physik, Wismarsche Straße 43-45, 18051 Rostock, Germany
Combination of different techniques for heat capacity spectroscopy and temperature-modulated calorimetry allows the determination of complex heat capacity in a wide frequency range. We study the dynamic glass transition and its corresponding temperature-dependent cooperativity of polymers. An AC-chip calorimeter gives the possibility to decrease the size of the measured sample, hence increases the sensitivity and frequency range. However, the investigation of the dynamic glass transition is still limited to the frequencies up to a few kHz, due to capacitive coupling between heater driving voltage and thermopile voltage at high frequencies. A new AC-chip calorimeter with laser heating, which decouple the temperature measurement and heating, is capable of measuring the glass transition temperature of thin film samples in nanogram range and in the frequency range up to 500 kHz. The dynamic glass transition of polystyrene and poly(methyl methacrylate) was studied from 10−5 Hz to 500 kHz.