TEMPERATURE MODULATED CALORIMETRY AND DIELECTRIC-SPECTROSCOPY IN THE GLASS-TRANSITION REGION OF POLYMERS

The results from temperature modulated DSC in the glass transition reg ion of amorphous and semicrystalline polymers are described with the l inear response approach. The real and the imaginary part of the comple x heat capacity are discussed. The findings are compared with those of dielectric spectroscopy. The frequency dependent glass transition tem perature can be fitted with a VFT-equation. The transition frequencies are decreased by 0.5 to 1 orders of magnitude compared to dielectric measurements. Cooling rates from standard DSC are transformed into fre quencies. The glass transition temperatures are also approximated by t he VFT-fit from the temperature modulated measurements. The difference s in the shape of the curves from amorphous and semicrystalline sample s are discussed.