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Gas permeability of polyimides and polypyrrolone derived from 2,2′‐ bis ( p ‐trimellitoxyphenyl)hexafluoropropane dianhydride
Author(s) -
Gao Xuesong,
Lu Fengcai
Publication year - 1996
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19960222)59:8<1315::aid-app15>3.0.co;2-4
Subject(s) - selectivity , permeability (electromagnetism) , polymer , polymer chemistry , chemistry , chemical engineering , materials science , semipermeable membrane , organic chemistry , membrane , catalysis , biochemistry , engineering
The permeability coefficients for H 2 , O 2 , and N 2 in four polyimides and one polypyrrolone based on 2,2′‐ bis ( p ‐trimellitoxyphenyl)hexafluoropropane dianhydride were determined at 30°C and 1 atm. Systematic variations in chemical structure were found to lead to significant changes in permeabilities and selectivities. The relationship between the chemical structure of the polymers, some of their physical properties ( d ‐spa+ing, fractional free volume), and their gas permeability behavior are discussed. Introduction of 2 flexible segments tends to increase permeability but decrease selectivity. Structural moieties, which simultaneously inhibit chain packing and intrasegmental mobility, may increase permeability while maintaining selectivity. Temperature dependency of gas permeabilities was also reported for polypyrrolone. © 1996 John Wiley & Sons, Inc.