Molecular dynamics of copolyester/clay nanocomposites as investigated by viscoelastic and dielectric analysis

TitleMolecular dynamics of copolyester/clay nanocomposites as investigated by viscoelastic and dielectric analysis
Publication TypeJournal Article
Year of Publication2008
AuthorsKalgaonkar, RA, Jog, JPrakash
JournalJournal of Polymer Science Part B-Polymer Physics
Volume46
Issue23
Pagination2539-2555
Date PublishedDEC
Type of ArticleArticle
ISSN0887-6266
Keywordsclay, Dielectric relaxation, Nanocomposites, polyesters
Abstract

We have investigated the molecular dynamics of poly(ethylene glycol-co-cycloxeane-1,4-dimethanol terephthalate) (PETG) nanocomposites based on a organically modified layered silicate. Intercalated namocomposites were prepared by melt compounding technique as evidenced from the X-ray diffraction and transmission electron microscopy studies. Two relaxation processes were observed in pure PETG as well as in the nanocomposites. The low-temperature beta-process was assigned to the local motions of C=O polar groups and the alpha-process was due to the glass-rubber transition or the segmental relaxations associated with the polymer chain backbone. Presence of layered silicates accelerated alpha-relaxation dynamics in the nanocomposites accompanied by a depression in T(g) which was attributed to the reduced intermolecular cooperativity between intercalated polymers chains. Additionally, a direct comparison between the viscoelastic and dielectric studies shows excellent agreement between the accelerated alpha dynamics of the nanocomposites. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 2539-2555, 2008

DOI10.1002/polb.21603
Type of Journal (Indian or Foreign)Foreign
Impact Factor (IF)3.318
Divison category: 
Polymer Science & Engineering