ABSTRACT A series of novel poly(arylene ether ketone)s with hexasulfophenyl pendents (6F-PAEK-SPx... more ABSTRACT A series of novel poly(arylene ether ketone)s with hexasulfophenyl pendents (6F-PAEK-SPx) were synthesized by polycondensation reaction of commercial 4,4′-(hexafluoroisopropylidene)diphenol (6FBPA), 4,4′-difluorobenzophenone and a new difluoride monomer, and followed by a post sulfonation modification with chlorosulfonic acid. Controlling of substituent positions and the degree of sulfonation were realized using quantities of the new difluoride monomer. The structure of 6F-PAEK-SPx was confirmed by 1H NMR and FT-IR instrument. The tough, flexible and transparent films of 6F-PAEK-SPx were obtained by solution casting. Those membranes with desired IEC values showed excellent thermal stability and mechanical properties. The membranes of 6F-PAEK-SPx copolymers containing hydrophobic main chain and hydrophilic micro-clustered pendent exhibited high proton conductivity and lower dimensional change value. The proton conductivity of 6F-PAEK-SP22 with the IEC of 1.77 meq/g was higher than that of Nafion 117 from 20 °C to 100 °C. The excellent properties of the membranes were attributed to the good hydrophobic/hydrophilic morphology of the membranes. The novel 6F-PAEK-SP copolymers combining the advantages of the well defined proton transport channels and enhanced physical properties will be the potential alternative materials to Nafion for PEMFC.
Journal of materials chemistry. A, Materials for energy and sustainability, 2013
ABSTRACT New difluoride monomer containing a biphenyl pendant group is designed and synthesized f... more ABSTRACT New difluoride monomer containing a biphenyl pendant group is designed and synthesized for preparing side chain style polyelectrolyte. As a result, a novel poly(arylene ether)s containing flexible disulfonic acid pendant are obtained by a two-step synthetic procedure. First, poly(arylene ether)s with electron-rich side groups as polymer precursor (P-x) are prepared from designed difluoride monomer, 4,4′-difluorobenzophenone (DFDPK), and 4,4′-(hexafluoroisopropylidene)diphenol (6FBPA) by nucleophilic polycondensation. Then objective sulfonated polymers (I-x) are obtained from P-x and chlorosulfonic acid by sulfonation reaction. Tough, flexible, and transparent membranes having high mechanical strength are obtained by solution casting of I-x polymer. The membrane I-x exhibits high proton conductivity and good dimensional stability, which attributes their special side chain style structure. For example, I-50 membrane (IEC = 1.32 meq. g−1) shows low swelling of 8.1% and comparable conductivity with Nafion 117 at 80 °C. Suitable morphology is observed in I-x membranes by SAXS test, which may explain that I-x possess perfect overall properties.
A series of microporous polyimide networks were preparedviaa novel two-step pathway combining pol... more A series of microporous polyimide networks were preparedviaa novel two-step pathway combining polymerization and crosslinking reactions.
ABSTRACT A series of novel poly(arylene ether ketone)s with hexasulfophenyl pendents (6F-PAEK-SPx... more ABSTRACT A series of novel poly(arylene ether ketone)s with hexasulfophenyl pendents (6F-PAEK-SPx) were synthesized by polycondensation reaction of commercial 4,4′-(hexafluoroisopropylidene)diphenol (6FBPA), 4,4′-difluorobenzophenone and a new difluoride monomer, and followed by a post sulfonation modification with chlorosulfonic acid. Controlling of substituent positions and the degree of sulfonation were realized using quantities of the new difluoride monomer. The structure of 6F-PAEK-SPx was confirmed by 1H NMR and FT-IR instrument. The tough, flexible and transparent films of 6F-PAEK-SPx were obtained by solution casting. Those membranes with desired IEC values showed excellent thermal stability and mechanical properties. The membranes of 6F-PAEK-SPx copolymers containing hydrophobic main chain and hydrophilic micro-clustered pendent exhibited high proton conductivity and lower dimensional change value. The proton conductivity of 6F-PAEK-SP22 with the IEC of 1.77 meq/g was higher than that of Nafion 117 from 20 °C to 100 °C. The excellent properties of the membranes were attributed to the good hydrophobic/hydrophilic morphology of the membranes. The novel 6F-PAEK-SP copolymers combining the advantages of the well defined proton transport channels and enhanced physical properties will be the potential alternative materials to Nafion for PEMFC.
Journal of materials chemistry. A, Materials for energy and sustainability, 2013
ABSTRACT New difluoride monomer containing a biphenyl pendant group is designed and synthesized f... more ABSTRACT New difluoride monomer containing a biphenyl pendant group is designed and synthesized for preparing side chain style polyelectrolyte. As a result, a novel poly(arylene ether)s containing flexible disulfonic acid pendant are obtained by a two-step synthetic procedure. First, poly(arylene ether)s with electron-rich side groups as polymer precursor (P-x) are prepared from designed difluoride monomer, 4,4′-difluorobenzophenone (DFDPK), and 4,4′-(hexafluoroisopropylidene)diphenol (6FBPA) by nucleophilic polycondensation. Then objective sulfonated polymers (I-x) are obtained from P-x and chlorosulfonic acid by sulfonation reaction. Tough, flexible, and transparent membranes having high mechanical strength are obtained by solution casting of I-x polymer. The membrane I-x exhibits high proton conductivity and good dimensional stability, which attributes their special side chain style structure. For example, I-50 membrane (IEC = 1.32 meq. g−1) shows low swelling of 8.1% and comparable conductivity with Nafion 117 at 80 °C. Suitable morphology is observed in I-x membranes by SAXS test, which may explain that I-x possess perfect overall properties.
A series of microporous polyimide networks were preparedviaa novel two-step pathway combining pol... more A series of microporous polyimide networks were preparedviaa novel two-step pathway combining polymerization and crosslinking reactions.
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