ISSN:
0887-6266
Keywords:
enthalpy relaxation
;
conformational energy
;
free volume
;
glass transition
;
side chains
;
physical ageing
;
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
The enthalpy changes ΔH∞ between a poly(vinyl acetate) glass formed by rapid cooling and the corresponding fully relaxed glass have been estimated at four temperatures below the glass transition. The values obtained were different to those expected by extrapolating liquid behavior below the glass transition and were found to agree well with the predictions of a simple expression for the combined main chain conformational and free volume contributions to enthalpy. Conformational contributions from the side chain alone were also considered but were not required to obtain agreement with experiment. It can be concluded that the side chains remained mobile below the glass transition and do not contribute to the heat capacity discontinuity at Tg. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35: 1107-1116, 1997
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
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