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Thickness-dependent sorption and effects of physical aging in a polyimide sample

✍ Scribed by David Punsalan; William J. Koros

Publisher
John Wiley and Sons
Year
2005
Tongue
English
Weight
115 KB
Volume
96
Category
Article
ISSN
0021-8995

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✦ Synopsis

Abstract

The solubility of a relatively noninteracting gas (CH~4~) was measured and compared for samples of vastly different thicknesses (25.4 vs 0.1 μm) to investigate the possibility of thickness‐dependent sorption and physical aging in glassy polymers. Changes in the sorption due to physical aging in these dense samples were observed and compared. To further compare the tendency of free‐volume relaxations in samples of different thicknesses, a variety of conditioning sorption tests were performed in which increases in the CH~4~ sorption due to high‐pressure CO~2~ exposure were observed and then compared after sample degassing. The reduction in CH~4~ solubility was related to excess free‐volume relaxations, and response comparisons of samples of widely different film thicknesses supported the notion of thickness‐dependent physical aging in glassy polymers. To the authors' knowledge, this was the first direct observation of a significant differences in gas solubility in glassy polymers due to the film thickness and aging time. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 1115–1121, 2005

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