A COMPARATIVE DIELECTRIC STUDY ON THE MOLECULAR-DYNAMICS OF THE LIQUID-CRYSTALLINE AND THE AMORPHOUS STATE OF COPOLYESTERS

Authors
AHUMADA O EZQUERRA TA NOGALES A BALTACALLEJA FJ ZACHMANN HG
Citation
O. Ahumada et al., A COMPARATIVE DIELECTRIC STUDY ON THE MOLECULAR-DYNAMICS OF THE LIQUID-CRYSTALLINE AND THE AMORPHOUS STATE OF COPOLYESTERS, Macromolecular rapid communications, 16(12), 1995, pp. 899-904
Citations number
12
Categorie Soggetti
Polymer Sciences
Journal title
Macromolecular rapid communications → ACNP
ISSN journal
10221336
Volume
16
Issue
12
Year of publication
1995
Pages
899 - 904
Database
ISI
SICI code
1022-1336(1995)16:12<899:ACDSOT>2.0.ZU;2-R
Abstract
The complex dielectric permittivity has been measured in the 10(3)-10( 6) Hz frequency range for selected random copolyesters of poly(ethylen e terephthalate). The variation of the dielectric properties with temp erature has been qualitatively related mainly to two processes. The al pha relaxation, which is associated with the glass transition, has bee n shown to be dependent on the molecular order of the systems. The bet a relaxation process has been assigned to local motions of the ester g roups attached to both sides of the aromatic rings. The beta process i s also shown to exhibit a dependence on molecular order.