DSC STUDY OF MAIN RELAXATIONS IN THE POLY(IMIDE-DIMETHYLSILOXANE) BLOCK-COPOLYMERS

Citation
Va. Bershtein et al., DSC STUDY OF MAIN RELAXATIONS IN THE POLY(IMIDE-DIMETHYLSILOXANE) BLOCK-COPOLYMERS, Journal of macromolecular science. Physics, B37(6), 1998, pp. 747-763
Citations number
26
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Polymer Sciences
ISSN journal
0022-2348
Volume
B37
Issue
6
Year of publication
1998
Pages
747 - 763
Database
ISI
SICI code
0022-2348(1998)B37:6<747:DSOMRI>2.0.ZU;2-G
Abstract
The segmental dynamics in, a series of alternating, phase-separated po ly(imide dimethylsiloxane) (PI/PDMS) block copolymers has been studied by differential scanning calorimetry (DSC) over the temperature range of 100-630 K, covering the regions of the glass transition and beta-r elaxation for soft and rigid blocks. The PI blocks had degrees of poly merization that ranged from 6 to 30, and the PDMS moiety content varie d from 10 to 47 mass%. Complex behavior of the low-temperature, PDMS b lock glass transition characteristics was shown, and the conditions fo r maintaining the PI domains with high T-g, providing thermal stabilit y for these block copolymers, were ascertained. The peculiarities of s egmental dynamics and its heterogeneity observed within the glass tran sition could be interpreted by using as a basis the concept of the com mon segmental nature of the alpha- and beta-transitions in flexible-ch ain polymers.