Relationships between the chemical structures and the solubility, diffusivity, and permselectivity of propylene and propane in 6FDA-based polyimides

Shimazu, Akira; Miyazaki, Tsukasa; Maeda, Masatoshi; Ikeda, Keisuke

doi:10.1002/1099-0488(20001001)38:19<2525::aid-polb40>3.0.co;2-2

Cited by 89 publications

(46 citation statements)

References 25 publications

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“…of magnitude, and this decrease in permeability was almost exclusively associated with a decrease in gas diffusivity. 70 The effect of ether versus hexafluoroisopropylidene structure is even more pronounced for the TR polymers. In the polyimides, for example, structural modification of ether to hexafluoroisopropylidene functionality increases CO 2 permeability by a factor of 8, but, for their corresponding TR polymers, this structural modification increases CO 2 permeability by a factor of 62.…”

Section: Guo Et Al and Sanders Et Al Investigated Pure-gas Permeabimentioning

confidence: 99%

Effect of polymer structure on gas transport properties of selected aromatic polyimides, polyamides and TR polymers

Smith

Hernández

Gleason

et al. 2015

Journal of Membrane Science

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GRAPHICAL ABSTRACT HIGHLIGHTSx Several TR polymer precursors and TR polymers were synthesized.x Thermal rearrangement reactivity was investigated for each structure.x H 2 , CH 4 , N 2 , O 2 , and CO 2 permeabilities track with free volume.x CO 2 hysteresis loops were used to characterize conditioning and plasticization. x APAF-6FDA TR has above-upper bound properties for propylene/propane separation. ABSTRACTThermally rearranged (TR) polymers are formed through a thermally induced solid-state reaction of polyimides or polyamides that contain nucleophilic reactive groups ortho-positioned to their diamine. Naturally, the transport properties of TR polymers are intimately related to the chemical structure and reactivity of their precursors. Herein, we report characterization and transport properties for three poly(hydroxyimide) precursors prepared via thermal imidization in solution and for their corresponding TR polymers.Structural modifications to the polymer backbone can be used to control thermal rearrangement reaction kinetics. In regards to TR polymer formation, samples prepared from diamines with biphenyl functionality reacted more efficiently than those prepared from diamines with hexafluoroisopropylidene-linked aromatic units. However, hexafluoroisopropylidene functional units provided the highest combinations of permeability and selectivity for separations involving H 2 , N 2 , O 2 , CH 4 , and CO 2 .Differences in permeability between samples correlated well with changes in free volume, and 3 poly(hydroxyimide)s showed unusually high selectivities for their given free volume. The effect of synthesis route was also investigated for a specific TR polymer derived from 3,3'-dihydroxy-4,4'-diamino-biphenyl (HAB) and 2,2'-bis-(3,4-dicarboxyphenyl) hexafluoropropane dianhydride (6FDA). Poly(hydroxyimide) precursors prepared via thermal imidization in solution and thermal imidization in the solid-state showed nearly identical permeabilities and selectivities regardless of synthesis route. However, after thermal rearrangement, the TR polymers prepared from polyimides synthesized via solid-state imidization have higher gas permeabilities than their solutionimidized analogs. In addition to light gas permeabilities, plasticization effects were investigated with CO 2 hysteresis loops for all samples, and pure-gas olefin/paraffin permeabilities were determined for a TR polymer derived from 2,2-bis (3-amino-4-hydroxyphenyl)-hexafluoropropane (APAF) and 6FDA. With the exception of HAB-6FDA polyimides, pure-gas CO 2 feed pressures up to approximately 50 bar do not reveal a plasticization pressure point, but conditioning effects are observed for most samples.APAF-6FDA TR polymers have pure-gas permeabilities and selectivities beyond the propylene/propane upper bound.

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Section: Guo Et Al and Sanders Et Al Investigated Pure-gas Permeabimentioning

confidence: 99%

Effect of polymer structure on gas transport properties of selected aromatic polyimides, polyamides and TR polymers

Smith

Hernández

Gleason

et al. 2015

Journal of Membrane Science

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“…Numerous data in the literature pertaining to C 3 H 6 /C 3 H 8 separation have been reported with unreproducibly high selectivities due to non-steady-state experiments involving transient C 3 H 8 data [45,46]. Additionally, in the event of plasticization, permeabilities may continue to steadily rise over time [47] and thus it is important to consider the timedependence of the data.…”

Section: Mixed-gas Time Dependencementioning

confidence: 99%

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

Swaidan

Ghanem

Swaidan

et al. 2015

Journal of Membrane Science

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Cite this article as: Ramy J. Swaidan, Bader Ghanem, Raja Swaidan, Eric Litwiller, Ingo Pinnau, Pure-and mixed-gas propylene/propane permeation properties of spiro-and triptycene-based microporous polyimides, Journal of Membrane Science, http://dx.doi.org/10. 1016/j.memsci.2015.05.044 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting galley proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. 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

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“…It has been found that polymeric membranes, e.g., silicone rubber, polysulfone, cellulose acetate, PDMS, 1,2-polybutadiene and polyethylene are not suitable for this kind of separation because the separation factors are far too low [44–46]. Much better separation characteristics were achieved with polyimides as membrane materials [11,45,47–49]. …”

Section: Olefin/paraffin Separationmentioning

confidence: 99%

Functionalized copolyimide membranes for the separation of gaseous and liquid mixtures

Schmeling¹,

Konietzny²,

Sieffert³

et al. 2010

Beilstein J. Org. Chem.

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SummaryFunctionalized copolyimides continue to attract much attention as membrane materials because they can fulfill the demands for industrial applications. Thus not only good separation characteristics but also high temperature stability and chemical resistance are required. Furthermore, it is very important that membrane materials are resistant to plasticization since it has been shown that this phenomenon leads to a significant increase in permeability with a dramatic loss in selectivity. Plasticization effects occur with most polymer membranes at high CO2 concentrations and pressures, respectively. Plasticization effects are also observed with higher hydrocarbons such as propylene, propane, aromatics or sulfur containing aromatics. Unfortunately, these components are present in mixtures of high commercial relevance and can be separated economically by single membrane units or hybrid processes where conventional separation units are combined with membrane-based processes. In this paper the advantages of carboxy group containing 6FDA (4,4′-hexafluoroisopropylidene diphthalic anhydride) -copolyimides are discussed based on the experimental results for non cross-linked, ionically and covalently cross-linked membrane materials with respect to the separation of olefins/paraffins, e.g. propylene/propane, aromatic/aliphatic separation e.g. benzene/cyclohexane as well as high pressure gas separations, e.g. CO2/CH4 mixtures. In addition, opportunities for implementing the membrane units in conventional separation processes are discussed.

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Relationships between the chemical structures and the solubility, diffusivity, and permselectivity of propylene and propane in 6FDA-based polyimides

Cited by 89 publications

References 25 publications

Effect of polymer structure on gas transport properties of selected aromatic polyimides, polyamides and TR polymers

Effect of polymer structure on gas transport properties of selected aromatic polyimides, polyamides and TR polymers

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

Functionalized copolyimide membranes for the separation of gaseous and liquid mixtures

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