Pure- and mixed-gas propylene/propane permeation properties of spiro- and triptycene-based microporous polyimides

Ramy J. Swaidan, Bader Ghanem, Raja Swaidan, Eric Litwiller, Ingo Pinnau

Research output: Contribution to journalArticlepeer-review

29 Scopus citations

Abstract

Solution-processable polyimides of intrinsic microporosity (PIM-PIs) comprising relatively inflexible and contorted backbones have demonstrated outstanding molecular-sieving behavior in membrane-based separation of gas/gas pairs. In this work, the effects of systematically increasing intra-chain rigidity on the propylene/propane separation properties were compared for PIM-PIs made from 2,3,5,6-tetramethyl-1,4-phenylene diamine (TMPD) and (i) spiro-centered dianhyride (SPDA-TMPD or PIM-PI-1) and (ii) 9,10-diisopropyltriptycene-based dianhydride (TPDA-TMPD or KAUST PI-1). Pure-gas experiments at 2 bar and 35 oC showed significant increases in C3H6 permeability and C3H6/C3H8 selectivity by transitioning from PIM-PI-1 (P(C3H6)=393 Barrer, α(C3H6/C3H8)=6) to KAUST-PI-1 (P(C3H6)=817 Barrer, α(C3H6/C3H8)=16), positioning KAUST-PI-1 considerably above the experimentally observed pure-gas C3H6/C3H8 polymer upper bound. However, 50:50 C3H6/C3H8 mixed-gas feeds induced significant losses in C3H6 permeability and C3H6/C3H8 selectivity relative to the 2 bar pure-gas data for PIM-PI-1 and KAUST-PI-1 as the C3H6/C3H8 selectivity dropped from 6 to 3 and 16 to 5, respectively, at 2 bar C3H6 partial pressure due to plasticization and competitive sorption.
Original languageEnglish (US)
Pages (from-to)116-122
Number of pages7
JournalJournal of Membrane Science
Volume492
DOIs
StatePublished - Jun 6 2015

ASJC Scopus subject areas

  • Biochemistry
  • Filtration and Separation
  • Materials Science(all)
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'Pure- and mixed-gas propylene/propane permeation properties of spiro- and triptycene-based microporous polyimides'. Together they form a unique fingerprint.

Cite this