Synthesis and Characterization of Poly(arylene ether ketone)s Bearing Pendant Sulfonic Acid Groups for Proton Exchange Membrane Materials
A bisphenol monomer (2,5-dimethoxy)phenylhydroquinone was prepared and further polymerized to obtain poly(arylene ether ketone) copolymers containing methoxy groups. After demethylation and sulfobutylation, a series of novel poly(arylene ether ketone)s bearing pendant sulfonic acid group (SPAEKs) with different sulfonation content were obtained. The chemical structures of all the copolymers were analyzed by 1H NMR and 13C NMR spectra. Flexible and tough membranes with reasonably good mechanical properties were prepared. The resulting side-chain-type SPAEK membranes showed good dimensional stability, and their water uptake and swelling ratio were lower than those of conventional main-chain-type SPAEK membranes with similar ion exchange capacity. Proton conductivities of these side-chain-type sulfonated copolymers were higher than 0.01 S/cm and increased gradually with increasing temperature. Their methanol permeability values were in the range of 1.97 × 10−7–5.81 × 10−7 cm2/s, which were much lower than that of Nafion 117. A combination of suitable proton conductivities, low water uptake, low swelling ratio, and high methanol resistance for these side-chain-type SPAEK films indicated that they may be good candidate material for proton exchange membrane in fuel cell applications. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2010
Figures in this publication
Available from: Rajdeep Mukherjee
- "However, the practical application of the PFSA polymers in large scale is limited to some extent due to the high methanol permeability, low conductivity at high temperature and high costs of these materials . To address all these problems, over the years several classes of copolymers were synthesized as potential PEM materials such as sulfonated poly(arylene ether sulfone)s   , sulfonated poly(ether ether ketone)s    , sulfonated polyimides    , sulfonated poly(benzimidazole)s    and sulfonated polytriazoles   . "
[Show abstract] [Hide abstract]
ABSTRACT: A series of new fluorinated sulfonated polytriazoles with varying degree of sulfonation was synthesized using the click reaction of a new diazide monomer; 4,4-bis[3-trifluoromethyl-4(4-azidophenoxy)phenyl] biphenyl (QAZ) and 4,4'-diazido-2,2'-stilbenedisulfonic acid disodium salt (DADSDB) with 4,4'-(propane-2,2-diyl)bis((prop-2-ynyloxy)benzene) (BPEBPA). The structures of the polytriazoles were confirmed by FTIR and NMR (H-1, C-13 and F-19) spectroscopy. The polytriazoles exhibit high molecular weights, and good solubility and film forming capabilities, combined with high thermal and chemical stabilities, low water uptake, good dimensional stability and high mechanical properties which makes them interesting materials as proton exchange membranes. TEM images of the polytriazole membranes showed nanophase separated morphology with ionic clusters in the range of 5-65 nm. The proton conductivities of the fluorinated membranes were found in the range of 12-76 mS/cm at 80 degrees C in water. A maximum value of even 112 mS/cm was achieved for the non-fluorinated sample.
[Show abstract] [Hide abstract]
ABSTRACT: Sulfonated poly(arylene ether)s with high content of phosphine oxide moieties were achieved by polycondensation of bis(4-hydroxyphenyl)phenylphosphine oxide with sulfonated bis(4-fluorodiphenyl)phenyl phosphine oxide and bis(4-fluorophenyl)phenyl phosphine oxide (or decafluorobiphenyl) for the first time. The high content phosphine-oxide moieties are expected to improve the oxidative stability of membranes, while the decafluorobiphenyl units were used to depress the swelling. The studies illustrated that all these membranes exhibited outstanding oxidative stability because of high content phosphine oxide moieties. On the other hand, the membranes with decafluorobiphenyl moieties (sPEPOF) displayed low swelling. This originates from these hydrophobic groups because they facilitated the membranes to form narrow ionic clusters. In summary, the sPEPOF membranes exhibited excellent overall properties. For instance, the sPEPOF membrane with 80% sulfonation degree displayed a proton conductivity of 0.077 S/cm as well as a swelling of 12% at 80°C. It also exhibited outstanding oxidative stability and high thermal stability.
[Show abstract] [Hide abstract]
ABSTRACT: Three series of fully aromatic ionomers with naphthalene moieties and pendant sulfobenzoyl side chains were prepared via K2CO3 mediated nucleophilic aromatic substitution reactions. The first series consisted of poly(arylene ether)s prepared by polycondensations of 2,6-difluoro-2′-sulfobenzophenone (DFSBP) and 2,6-dihydroxynaphthalene or 2,7-dihydroxynaphthalene (2,7-DHN). In the second series, copoly(arylene ether nitrile)s with different ion-exchange capacities (IECs) were prepared by polycondensations of DFSBP, 2,6-difluorobenzonitrile (DFBN), and 2,7-DHN. In the third series, bis(4-fluorophenyl)sulfone was used instead of DFBN to prepare copoly(arylene ether sulfone)s. Thus, all the ionomers had sulfonic acid units placed in stable positions close to the electron withdrawing ketone link of the side chains. Mechanically strong proton-exchange membranes with IECs between 1.1 and 2.3 meq g−1 were cast from dimethylsulfoxide solutions. High thermal stability was indicted by high degradation temperatures between 266 and 287 °C (1 °C min−1 under air) and high glass transition temperatures between 245 and 306 °C, depending on the IEC. The copolymer membranes reached proton conductivities of 0.3 S cm−1 under fully humidified conditions. At IECs above ∼1.6 meq g−1, the copolymer membranes reached higher proton conductivities than Nafion® in the range between −20 and 120 °C. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011
Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.