Please use this identifier to cite or link to this item:
|Title:||Permeability of polyimides derived from non-coplanar diamines and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride|
|Citation:||Xu, J.W., Chng, M.L., Chung, T.S., He, C.B., Wang, R. (2003-07-10). Permeability of polyimides derived from non-coplanar diamines and 4,4′-(hexafluoroisopropylidene)diphthalic anhydride. Polymer 44 (16) : 4715-4721. ScholarBank@NUS Repository. https://doi.org/10.1016/S0032-3861(03)00430-0|
|Abstract:||A series of polyimides including a non-coplanar moiety were synthesized in order to investigate the effect on gas permeability and selectivity. The gas permeation properties of He, H2, O2, N2, CH4 and CO2 were measured using a constant-volume method. Only 6FDA-terphenyl consisting of laterally attached phenyl groups shows a substantial increase because its terphenyl moiety is a rigid structure with a high aspect ratio. The order of permeability increase from 6FDA-phenyl to 6FDA-terphenyl is consistent with the calculated fraction free volume and measured permittivity. It is observed that the most gain in permeability for 6FDA-terphenyl polyimide arises from the enhancement in apparent diffusion coefficient, while the permeability increase for 6FDA-biphenyl is mainly due to the increase in solubility. A relationship of diffusivity vs. gas penetrant size as well as gas solubility vs. critical temperature of gas penetrant was also investigated. © 2003 Elsevier Science Ltd. All rights reserved.|
|Appears in Collections:||Staff Publications|
Show full item record
Files in This Item:
There are no files associated with this item.
checked on Jul 17, 2018
WEB OF SCIENCETM
checked on Jun 27, 2018
checked on Jun 8, 2018
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.