Effect of thermal annealing on the gas permeability of HIQ-40 films

✍ Scribed by J. Y. Park; D. R. Paul; I. Haider; M. Jaffe

• Publisher: John Wiley and Sons
• Year: 1996
• Tongue: English
• Weight: 381 KB
• Volume: 34
• Category: Article
• ISSN: 0887-6266
• DOI: 10.1002/(sici)1099-0488(19960730)34:10<1741::aid-polb4>3.0.co;2-t

✦ Synopsis

The copolyester formed from 40 mol% p-hydroxybenzoic acid (H), 30 mol% isophthalic acid (I), and 30 mol% hydroquinone (Q), designated as HIQ-40, forms isotropic, amorphous films when appropriately cast from a solvent. Thermal annealing leads to a mesogenic texture and some level of crystallinity. It is shown that these ordering processes lead to dramatic reductions in gas permeability; the magnitude of the decrease increases with the size of the penetrant. The current results are consistent with previously reported sorption data for acetone in HIQ-40.