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 CO2permeabilities similar to other polyimide‐ionenes and CO2/CH4and CO2/N2permselectivities that were relatively higher than other polyimide‐ionenes.
A new series of six imidazolium‐based ionenes containing aromatic amide linkages has been developed. These ionene‐polyamides are all constitutional isomers varying in the regiochemistry of the amide linkages (para, meta) and xylyl linkages (ortho, meta, para) along the polymer backbone. The physical properties as well as the gas separation behaviors of the corresponding membranes have been extensively studied. These ionene‐polyamide membranes show excellent thermal and mechanical stabilities, together with self‐healing and shape memory characteristics. Most importantly, [TC‐API(
- NSF-PAR ID:
- 10461535
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Polymer International
- Volume:
- 68
- Issue:
- 6
- ISSN:
- 0959-8103
- Page Range / eLocation ID:
- p. 1123-1129
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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