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Gas Separation Performance of Carbon Molecular Sieve Membranes Based on 6FDA‐mPDA/DABA (3:2) Polyimide
Author(s) -
Qiu Wulin,
Zhang Kuang,
Li Fuyue Stephanie,
Zhang Ke,
Koros William J.
Publication year - 2014
Publication title -
chemsuschem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.412
H-Index - 157
eISSN - 1864-564X
pISSN - 1864-5631
DOI - 10.1002/cssc.201300851
Subject(s) - membrane , barrer , polyimide , selectivity , permeation , gas separation , molecular sieve , pyrolysis , chemical engineering , polymer , polymer chemistry , materials science , synthetic membrane , thermogravimetric analysis , permeability (electromagnetism) , fourier transform infrared spectroscopy , chemistry , organic chemistry , adsorption , catalysis , biochemistry , layer (electronics) , engineering
6FDA‐mPDA/DABA (3:2) polyimide was synthesized and characterized for uncross‐linked, thermally crosslinked, and carbon molecular sieve (CMS) membranes. The membranes were characterized with thermogravimetric analysis, FTIR spectroscopy, wide‐angle X‐ray diffraction, and gas permeation tests. Variations in the d spacing, the formation of pore structures, and changes in the pore sizes of the CMS membranes were discussed in relation to pyrolysis protocols. The uncross‐linked polymer membranes showed high CO 2 /CH 4 selectivity, whereas thermally crosslinked membranes exhibited significantly improved CO 2 permeability and excellent CO 2 plasticization resistance. The CMS membranes showed even higher CO 2 permeability and CO 2 /CH 4 selectivity. An increase in the pyrolysis temperature resulted in CMS membranes with lower gas permeability but higher selectivity. The 550 °C pyrolyzed CMS membranes showed CO 2 permeability as high as 14 750 Barrer with CO 2 /CH 4 selectivity of approximately 52. Even 800 °C pyrolyzed CMS membranes still showed high CO 2 permeability of 2610 Barrer with high CO 2 /CH 4 selectivity of approximately 118. Both polymer membranes and the CMS membranes are very attractive in aggressive natural gas purification applications.