TY - JOUR
T1 - Gas Permeation and Physical Aging Properties of Iptycene Diamine-Based Microporous Polyimides
AU - Alghunaimi, Fahd
AU - Ghanem, Bader
AU - Alaslai, Nasser Y.
AU - Swaidan, Raja
AU - Litwiller, Eric
AU - Pinnau, Ingo
N1 - KAUST Repository Item: Exported on 2020-10-01
PY - 2015/5/12
Y1 - 2015/5/12
N2 - The synthesis and gas permeation properties of two 6FDA-dianhydride-based polyimides prepared from 2,6-diaminotriptycene (6FDA-DAT1) and its extended iptycene analog (6FDA-DAT2) are reported. The additional benzene ring on the extended triptycene moiety in 6FDA–DAT2 increases the free volume over 6FDA-DAT1 and reduces the chain packing efficiency. The BET surface area based on nitrogen adsorption in 6FDA-DAT2 (450 m2g−1) is ~40% greater than that of 6FDA-DAT1 (320 m2g−1). 6FDA-DAT1 shows a CO2 permeability of 120 Barrer and CO2/CH4 selectivity of 38, whereas 6FDA-DAT2 exhibits a 75% increase in CO2 permeability to 210 Barrer coupled with a moderate decrease in selectivity (CO2/CH4=30). Interestingly, minimal physical aging was observed over 150 days for both polymers and attributed to the high internal free volume of the shape-persistent iptycene geometries. The aged polyimides maintained CO2/CH4 selectivities of 25-35 along with high CO2 permeabilities of 90-120 Barrer up to partial CO2 pressures of 10 bar of an aggressive 50:50 CO2:CH4 mixed-gas feed, suggesting potential application in membranes for natural gas sweetening.
AB - The synthesis and gas permeation properties of two 6FDA-dianhydride-based polyimides prepared from 2,6-diaminotriptycene (6FDA-DAT1) and its extended iptycene analog (6FDA-DAT2) are reported. The additional benzene ring on the extended triptycene moiety in 6FDA–DAT2 increases the free volume over 6FDA-DAT1 and reduces the chain packing efficiency. The BET surface area based on nitrogen adsorption in 6FDA-DAT2 (450 m2g−1) is ~40% greater than that of 6FDA-DAT1 (320 m2g−1). 6FDA-DAT1 shows a CO2 permeability of 120 Barrer and CO2/CH4 selectivity of 38, whereas 6FDA-DAT2 exhibits a 75% increase in CO2 permeability to 210 Barrer coupled with a moderate decrease in selectivity (CO2/CH4=30). Interestingly, minimal physical aging was observed over 150 days for both polymers and attributed to the high internal free volume of the shape-persistent iptycene geometries. The aged polyimides maintained CO2/CH4 selectivities of 25-35 along with high CO2 permeabilities of 90-120 Barrer up to partial CO2 pressures of 10 bar of an aggressive 50:50 CO2:CH4 mixed-gas feed, suggesting potential application in membranes for natural gas sweetening.
UR - http://hdl.handle.net/10754/553002
UR - http://linkinghub.elsevier.com/retrieve/pii/S0376738815004214
UR - http://www.scopus.com/inward/record.url?scp=84930225236&partnerID=8YFLogxK
U2 - 10.1016/j.memsci.2015.05.010
DO - 10.1016/j.memsci.2015.05.010
M3 - Article
SN - 0376-7388
VL - 490
SP - 321
EP - 327
JO - Journal of Membrane Science
JF - Journal of Membrane Science
ER -