The determination of the glass transition temperature by thermally stimulated depolarization currents. Comparison with the performance of other techniques |
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| Authors: | Joaquim J Moura Ramos Hermínio P Diogo |
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| Institution: | 1. CQFM – Centro de Química-Física Molecular and IN ? Institute of Nanoscience and Nanotechnology, Instituto Superior Técnico, Universidade de Lisboa, Lisboa, Portugalmouraramos@tecnico.ulisboa.pt;3. CQE – Centro de Química Estrutural, Complexo I, IST, Universidade de Lisboa, Lisboa, Portugal |
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| Abstract: | Several experimental techniques are currently used for the determination of the glass transition temperature, Tg. Thermally stimulated depolarization currents (TSDC) is a thermal analysis technique whose experimental results display a very clean glass transition signature and that, nevertheless, is seldom used as a technique for Tg determination. In the present work we explain how to get the glass transition temperature from TSDC data, and we compare the values obtained for a vast number of glass forming systems (with Tgs in a wide range between ?145 and +180 °C and fragilities between m = 15 and m = 100), with the values obtained by differential scanning calorimetry (DSC) and dielectric relaxation spectroscopy (DRS). We conclude that the Tg determination by TSDC is direct, accurate and reproducible and that the obtained values correlate very well with those obtained by DSC and DRS. This general survey thus suggests TSDC as a valuable alternative technique for determining Tg. |
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| Keywords: | Thermally stimulated depolarization currents differential scanning calorimetry dielectric spectroscopy glass transition glass transition temperature |
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