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Titolo:
Dielectric relaxation behaviour of fluorinated aromatic poly(ether)s and poly(ether ketone)s
Autore:
Goodwin, AA; Atkinson, JR; Hay, JN; Mercer, FW;
Indirizzi:
Monash Univ, Clayton, Vic 3168, Australia Monash Univ Clayton Vic Australia 3168 Univ, Clayton, Vic 3168, Australia Univ Birmingham, Birmingham B15 2TT, W Midlands, England Univ Birmingham Birmingham W Midlands England B15 2TT W Midlands, England Raychem Corp, Res & Dev, Menlo Park, CA 94025 USA Raychem Corp Menlo ParkCA USA 94025 Res & Dev, Menlo Park, CA 94025 USA
Titolo Testata:
POLYMER
fascicolo: 6, volume: 40, anno: 1999,
pagine: 1515 - 1524
SICI:
0032-3861(199903)40:6<1515:DRBOFA>2.0.ZU;2-1
Fonte:
ISI
Lingua:
ENG
Soggetto:
RELATIVE PERMITTIVITY; GLASS-TRANSITION; ETHER KETONE); POLYIMIDE;
Keywords:
fluorinated polymers; dielectric relaxation spectroscopy; alpha-relaxation;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Physical, Chemical & Earth Sciences
Citazioni:
30
Recensione:
Indirizzi per estratti:
Indirizzo: Goodwin, AA Monash Univ, Clayton, Vic 3168, Australia Monash Univ ClaytonVic Australia 3168 n, Vic 3168, Australia
Citazione:
A.A. Goodwin et al., "Dielectric relaxation behaviour of fluorinated aromatic poly(ether)s and poly(ether ketone)s", POLYMER, 40(6), 1999, pp. 1515-1524

Abstract

Eight amorphous, thermoplastic aromatic poly(ether)s and poly(ether ketone)s, some containing fluorine, were investigated by dielectric relaxation spectroscopy over the frequency range 20-10(5) Hz and the temperature range -130-300 degrees C. For the polymers containing perfluorophenylene units, three relation processes were observed; one corresponding to the glass transition (or-relaxation), and a further two sub-T-g secondary process (beta- and gamma-processes). For polymers without perfluorophenylene units, a beta-process was not detected. The sub-T-g transitions followed Arrhenius behaviour and were sensitive to polymer structure and chain flexibility. The sub-ambient relaxation exhibited a strong dependence on absorbed moisture. The polymers containing perfluorophenylene units showed a significant decrease in dielectric permittivity at 100 kHz and this was attributed mainly to a reduced electronic polarisability. The alpha-relaxation strength of the perfluorinated polymers, which arises from dipolar motions, was also reduced. (C) 1998 Elsevier Science Ltd. All rights reserved.

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Documento generato il 23/09/20 alle ore 15:55:32