The gas permeation behavior of hexafluoro-dianhydride (6FDA)-durene/3,3′-diaminodiphenyl sulfone (DDS) polyimides was investigated by systematically varying the diamine ratios. Generally, the gas permeability, diffusion and solubility coefficients were found to decrease with increasing 3,3′-DDS diamine content. The permeability coefficients of H2, O2, N2 and CO2 decreased with the increasing order of kinetic diameters of the penetrant gases. However, the decrease in diffusion coefficients of O2, N2 and CO2 was in accordance with the effective diameters of the gas molecules. The permselectivity of gas pairs such as CO2/N2, O2/N2 and H2/N2 was enhanced with the incorporation of 3,3′-DDS moiety. The gas transport coefficients of the copolyimides predicted from the addition rule were compared with the experimental results. It was seen that gas permeation coefficients for the copolyimides slightly deviated from the predicted values. In contrast, the logarithm of gas permeation coefficients and the reciprocal of fractional free volume (1/FFV) exhibited a better correlation.
|Original language||English (US)|
|Number of pages||12|
|Journal||Journal of Membrane Science|
|State||Published - Jun 15 2002|
Bibliographical noteFunding Information:
The authors would like to thank BG Asia Pacific Pte. Ltd., Institute of Materials Research and Engineering (IMRE), Environmental Technology Institute (ETI), Economic Development Board of Singapore (EDB) and the National Science and Technology Board of Singapore (NSTB) for funding this project.
- 6FDA copolyimide
- Fractional free volume
ASJC Scopus subject areas
- Materials Science(all)
- Physical and Theoretical Chemistry
- Filtration and Separation