The temperature dependence of the gas permeability and sorption coefficients of a series of ladder-type polypyrrolones, 6FDA-TAB and 6FDA/PMDA-TAB copolymers, is reported at temperatures up to 80ยฐC. Knowledge of gas transport and sorption behavior at higher temperatures provides insights into these
Polypyrrolones for membrane gas separations. I. Structural comparison of gas transport and sorption properties
โ Scribed by Catherine M. Zimmerman; William J. Koros
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 313 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0887-6266
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โฆ Synopsis
Despite efforts by the membrane community to develop polymeric materials with improved O 2 /N 2 separation performance, limited progress has occurred for almost a decade. Molecular sieving media, which can exhibit gas separation properties superior to polymers, tend to be brittle and uneconomical to produce for large-scale membrane separation processes. Considering this, the polymer structures investigated in this work were designed to mimic aspects of the structure of molecular sieving media such as zeolites and carbon molecular sieves while maintaining the processability associated with polymers. Significantly attractive gas separation material properties were obtained using hyper rigid polypyrrolone copolymers with controlled packing disruptions between flat, packable segments. The gas transport properties in the materials changed dramatically as a result of different average interchain spacing. Moreover, all of the polypyrrolones studied in this work exhibited performance lying on or above the existing O 2 /N 2 upper bound trade-off line between permselectivity and permeability. These results, therefore, may point the way to a new cycle of membrane materials improvements for gas separations.
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