Dielectric relaxation spectroscopy of polyethylene terephthalate (PET) films

Neagu, E; Pissis, P; Apekis, L; Gomez Ribelles, JL

dc.contributor.author	Neagu, E	en
dc.contributor.author	Pissis, P	en
dc.contributor.author	Apekis, L	en
dc.contributor.author	Gomez Ribelles, JL	en
dc.date.accessioned	2014-03-01T01:12:46Z
dc.date.available	2014-03-01T01:12:46Z
dc.date.issued	1997	en
dc.identifier.issn	0022-3727	en
dc.identifier.uri	https://dspace.lib.ntua.gr/xmlui/handle/123456789/12236
dc.subject.classification	Physics, Applied	en
dc.subject.other	POLY(ETHYLENE-TEREPHTHALATE)	en
dc.subject.other	POLYMERS	en
dc.subject.other	CURRENTS	en
dc.subject.other	CONDUCTIVITY	en
dc.subject.other	CAPACITORS	en
dc.subject.other	TRANSIENT	en
dc.title	Dielectric relaxation spectroscopy of polyethylene terephthalate (PET) films	en
heal.type	journalArticle	en
heal.identifier.primary	10.1088/0022-3727/30/11/003	en
heal.identifier.secondary	http://dx.doi.org/10.1088/0022-3727/30/11/003	en
heal.language	English	en
heal.publicationDate	1997	en
heal.abstract	The dielectric properties of biaxially stretched polyethylene terephthalate (PET) films of 6 mu m thickness and 68% degree of crystallinity were investigated by means of dielectric relaxation spectroscopy in the frequency range 10(-2)-10(6) Hz and the temperature range 20-190 degrees C. Differencial scanning calorimetry (DSC), in the range 50-300 degrees C, was employed to investigate the thermal properties of the PET samples. Besides measuring the alpha relaxation associated with the glass transition and the secondary beta relaxation, special attention has been paid to the investigation of DC-conductivity-related effects. They give rise to high dielectric permittivity values and dielectric losses at low frequencies and high temperatures. The results are analysed within the complex permittivity formalism and discussed in terms of interfacial Maxwell-Wagner-Sillars polarization, the rho peak, conductivity relaxation, space-charge polarization, electrode polarization and DC conductivity. DC conductivity values determined from frequency plots of the AC conductivity follow the Vogel-Tamman-Fulcher equation at temperatures higher than the glass transition temperature, indicating that the charge-carrier transport mechanism is governed by the motion of the polymeric chains. On the basis of the temperature dependence of the DC conductivity PET is classified as a fragile system.	en
heal.publisher	IOP PUBLISHING LTD	en
heal.journalName	Journal of Physics D: Applied Physics	en
dc.identifier.doi	10.1088/0022-3727/30/11/003	en
dc.identifier.isi	ISI:A1997XE23200003	en
dc.identifier.volume	30	en
dc.identifier.issue	11	en
dc.identifier.spage	1551	en
dc.identifier.epage	1560	en