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A series of composite membranes based on sulfonated polyether ether ketone with embedded powdered heteropolycompounds was prepared and their electrochemical and thermal properties were studied. An increase in degree of sulfonation as well as introduction of these fillers resulted in increased T g and enhanced membrane hydrophilicity, bringing about a substantial gain in proton conductivity. The conductivity of the composite membranes exceeded 10 −2 S/cm at room temperature and reached values of about 10 −1 S/cm above 100 • C.

Synthesis and characterization of sulfonated poly(ether ether ketone) for proton exchange membranes Xing, P.; Robertson, Gilles; Guiver, Michael; Mikhailenko, S.; Wang, K.; Kaliaguine, S. AbstractSeries of sulfonated poly(ether ether ketone)s (SPEEKs) were prepared by sulfonation of commercial Victrex ® and Gatone ® PEEK for a comparative study of proton exchange membranes (PEM) intended for fuel cell applications. The degree of sulfonation (DS) of the sulfonated PEEK was determined from deuterated dimethyl sulfoxide (DMSO-d 6 ) solution of the purified polymers using 1 H NMR methods. The second method using a solvent suppression technique, in which DS results were obtained directly from 1 H NMR spectra of SPEEK dissolved in sulfuric acid (non-deuterated) reaction medium was evaluated. The variation between the two methods was determined. The room temperature sulfonation of PEEK, monitored directly by second 1 H NMR method, proceeded rapidly initially, reaching DS ∼ 0.8 within 1 week, but progressed slowly thereafter. A maximum DS of 1.0 was determined after 1 month at ambient temperature (∼22• C). The thermal properties of SPEEK were characterized by means of DSC and TGA. The mass averaged molecular weights M w of both Victrex ® and Gatone ® PEEK were estimated from intrinsic viscosities measured in sulfuric acid solutions. It was verified that higher temperature (55• C) did not induce any apparent chain degradation of Victrex ® (or Gatone ® ) PEEK by M w tests. The water uptake and swelling properties of prepared films were studied and the proton conductivities at different temperatures were measured. The conductivities of the SPEEKs were found to increase with increasing DS and temperatures. The effect of film casting solvents on the conductivities is also discussed.

Carboxylated polymers of intrinsic microporosity (carboxylated PIMs) are reported as potential high-performance materials for membrane-based gas separation. Carboxylated PIM membranes were prepared by in situ hydrolysis of the nitrile groups of PIM-1 films. Structural characterization was performed by Fourier transform infrared spectroscopy (FTIR) and proton nuclear magnetic resonance ( 1 H NMR). The degree of hydrolysis was determined by carbon elemental analysis. The thermal properties were evaluated by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). Compared with PIM-1, carboxylated PIMs with different degrees of hydrolysis have similar thermal and mechanical properties but show higher selectivity for gas pairs such as O 2 /N 2 ,CO 2 /N 2 , He/N 2 , and H 2 /N 2 with a corresponding decrease in permeability. Selectivity coupled to high permeability combines to exceed the Robeson upper-bound line for the O 2 /N 2 gas pair. This work demonstrates that significant improvements in gas separation properties may be obtained through postmodification of nitrile-based PIM membranes. The present work improves the understanding of the relationship of structure/permeation properties and also extends the PIM spectrum beyond those reported previously. In addition, the incorporation of carboxylic acid sites has the potential for further modification reactions such as grafting and cross-linking.

/npsi/ctrl?action=rtdoc&an=8934289&lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?action=rtdoc&an=8934289&lang=frAccess and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1021/ma801858dMacromolecules, 41, 24, pp. 9656-9662, 2008 Polymers of intrinsic microporosity containing trifluoromethyl and phenylsulfone groups as materials for membrane gas separation Du, Naiying; Robertson, Gilles; Song, Jingshe; Pinnau, Ingo; Thomas, Sylvie; Guiver, Michael Process and EnVironmental Technology, National Research Council of Canada, Ottawa, Ontario K1A 0R6, Canada, and Membrane Technology and Research Inc., 1360 Willow Road, Suite 103, Menlo Park, California 94025-1516 ReceiVed August 14, 2008 ReVised Manuscript ReceiVed October 14, 2008 ABSTRACT: A series of ladder copolymers and a homopolymer were synthesized via aromatic nucleophilic substitution polycondensation of 5,5′,6,6′-tetrahydroxy-3,3,3′,3′-tetramethylspirobisindane with tetrafluoroterephthalonitrile and a new monomer heptafluoro-p-tolylphenylsulfone as potential materials for membrane gas separation. Ladder polymers of this type comprising rigid and contorted chain structure have been commonly referred to as polymers of intrinsic microporosity (PIM) on account of their extraordinarily high fractional free volumes (FFV) and high gas permeability (P). The PIM polymer series of the present study was prepared in high molecular weight and low molecular weight distribution, using new experimental conditions of short reaction times and a high temperature of 160°C. Polymer chain d-spacing was investigated using wide-angle X-ray diffraction. Polymer free volume was calculated from the polymer density and specific van der Waals volume. Gas permeabilities for oxygen and carbon dioxide decreased with increasing content of the trifluoromethylphenylsulfone versus the dinitrile monomer within the copolymer, while the selectivities of gases against nitrogen increased. The pendent phenylsulfone groups likely reside within the interchain free volume of the rigid and contorted ladder polymer, acting to reduce gas permeability and increase selectivity, though with no overall loss of performance relative the Robeson upper bound. Evidence for this is a reduction in d-spacing and fractional free volume with increasing content of the trifluoromethylphenylsulfone versus the dinitrile monomer in the copolymer series. The relationship between the gas permeabilit...