ISSN:
0887-6266
Keywords:
glass transition
;
thermally stimulated currents (TSC)
;
relaxation
;
PVC
;
dielectric
;
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The thermally stimulated current-thermal sampling (TSC-TS) technique was used to study the broadened glass transition in conventional “atactic” poly(vinyl chloride), PVC. The activated parameters obtained from the TSC-TS data, mainly the apparent activation energy (Ea), characterize the breadth of glass transitions in a very sensitive way. These results are compared with those values of Ea obtained from the literature, using a recently proposed method of analyzing a.c. dielectric constants and their derivatives, over the temperature range of -100-130°C. Both techniques detect weak cooperative glass transition-like relaxations well below the main glass transition of ca. 80°C. As is the case with “atactic” PMMA, the data suggest that compositional heterogeneity related to a small fraction of predominantly isotactic sequences contribute to the broad glass transition extending ca. 60°C below the main glass transition in atactic PVC. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 913-918, 1998
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
