A dielectric relaxation study of the gamma-relaxation in tetramethylbisphenol A polycarbonate plasticized by tris(2-ethylhexyl) phosphate

Citation
Ak. Rizos et al., A dielectric relaxation study of the gamma-relaxation in tetramethylbisphenol A polycarbonate plasticized by tris(2-ethylhexyl) phosphate, MACROMOLEC, 32(23), 1999, pp. 7921-7924
Citations number
31
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
MACROMOLECULES
ISSN journal
00249297 → ACNP
Volume
32
Issue
23
Year of publication
1999
Pages
7921 - 7924
Database
ISI
SICI code
0024-9297(19991116)32:23<7921:ADRSOT>2.0.ZU;2-D
Abstract
Dielectric relaxation spectroscopy (DR) was employed to study the dynamics of glassy tetramethylbisphenol A polycarbonate (TMBPA-PC) containing variou s amounts of tris(2-ethylhexyl) phosphate (TOP) added as diluent molecules. The present data confirm that the gamma-relaxation dynamics, at constant f requency, shift to lower temperatures with increasing TOP content, an effec t observed for the first time by dynamic mechanical measurements. This beha vior of the gamma-relaxation in TMBPA-PC plasticized by TOP is to be contra sted with that in bisphenol A polycarbonate (BPA-PC) plasticized by TOP. In the latter case, the gamma-relaxation dynamics, at constant frequency, shi ft to higher temperatures with addition of TOP. These opposite trends of th e gamma-relaxation dynamics in two similar polycarbonates are surprising. H owever, the results can be rationalized by the coupling model.