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The dielectric behavior of glassy amorphous polymers at 2.45 GHz
Author(s) -
Chen M.,
Siochi E. J.,
Ward T. C.,
McGrath J. E.
Publication year - 1993
Publication title -
polymer engineering and science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.503
H-Index - 111
eISSN - 1548-2634
pISSN - 0032-3888
DOI - 10.1002/pen.760331704
Subject(s) - materials science , dielectric , relaxation (psychology) , amorphous solid , composite material , microwave , activation energy , glass transition , polymer , atmospheric temperature range , dielectric heating , thermodynamics , optoelectronics , organic chemistry , chemistry , psychology , social psychology , physics , quantum mechanics
The dielectric behavior of glassy thermoplastic polymer in the microwave frequency range was investigated. Specifically, the relationship between energy absorption and temperature for several thermoplastic systems was examined to test the theoretical basis for heating under microwave irradiation. Irradiation under traveling and standing wave conditions were explored. The heating rate versus temperature data at a frequency of 2.45 GHz yielded a microwave calorimetry procedure for examination of the dielectric and relaxation behaviors. Correlations were drawn between (a) the apparent activation energy and the critical temperature, and (b) the shape of the dielectric spectra at 2.45 GHz and its shape in the kHz region. WLF relationships were examined for glassy thermoplastics to show the difference in changing activation energy with temperature.