PRESSURE-DEPENDENT PHOTON-CORRELATION SPECTROSCOPIC INVESTIGATION OF POLY(PROPYLENE OXIDE) NEAR THE GLASS-TRANSITION

Authors
SMITH SW FREEMAN BD HALL CK
Citation
Sw. Smith et al., PRESSURE-DEPENDENT PHOTON-CORRELATION SPECTROSCOPIC INVESTIGATION OF POLY(PROPYLENE OXIDE) NEAR THE GLASS-TRANSITION, Macromolecules, 30(7), 1997, pp. 2052-2057
Citations number
27
Categorie Soggetti
Polymer Sciences
Journal title
Macromolecules → ACNP
ISSN journal
00249297
Volume
30
Issue
7
Year of publication
1997
Pages
2052 - 2057
Database
ISI
SICI code
0024-9297(1997)30:7<2052:PPSIOP>2.0.ZU;2-4
Abstract
The effect of pressure on structural relaxations in poly(propylene oxi de) (PPO; MW = 4000) near the glass transition has been determined usi ng photon correlation spectroscopy. Experimental results are reported for pressures ranging from 2.5 to 3.9 kbar at 253 K. The structural re laxation exhibits two distinct processes separated by similar to 3 ord ers of magnitude in time. This observation is consistent with results of dielectric relaxation studies of PPO. The faster relaxation is asso ciated with local segmental motions important in the glass-rubber tran sition. The mean relaxation time for the faster process exhibits an ex ponential dependence on pressure.