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6FDA ‐containing polyimide‐ionene + ionic liquid gas separation membranes
Author(s) -
Dennis Grayson P.,
O'Harra Kathryn E.,
Kammakakam Irshad,
Jones Tristin A.,
Mittenthal Max S.,
Flowers Brian S.,
Tuan Yi,
Jackson Enrique M.,
Bara Jason E.
Publication year - 2020
Publication title -
journal of polymer science
Language(s) - English
Resource type - Journals
eISSN - 2642-4169
pISSN - 2642-4150
DOI - 10.1002/pol.20200325
Subject(s) - polyimide , membrane , gas separation , ionic liquid , polymer chemistry , chemistry , polymer , intermolecular force , chemical engineering , permeability (electromagnetism) , imide , materials science , molecule , organic chemistry , catalysis , biochemistry , layer (electronics) , engineering
Polyimides (PI) synthesized from 4,4′‐(hexafluoroisopropylidene)diphthalic anhydride (6FDA) with various diamines have been frequently studied as gas separation membranes. The use of 6FDA in polyimides creates a bent structure than can increase fractional free volume (FFV) and gas permeability. Here, we demonstrate that 6FDA is also a useful building block for PI‐ionene materials, which contain cations directly within the polymer backbone. These new 6FDA‐containing PI‐ionenes were combined with several different imidazolium ionic liquids (ILs) to form thin membranes. The thermal properties of all the derivatives were investigated to determine the relationship between regiochemistry and degradation as well as the intermolecular forces that are present within these structures. The gas separation properties of these 6FDA‐containing PI‐ionene + IL materials were investigated, showing modest CO 2 permeabilities similar to other polyimide‐ionenes and CO 2 /CH 4 and CO 2 /N 2 permselectivities that were relatively higher than other polyimide‐ionenes.