Derived from a hydroquinone monomer, a series of poly(arylene ether ketone)s containing ethyl benzoate pendants were first prepared as starting materials via aromatic nucleophilic substitution polycondensations. Sulfonated analogues could be obtained by simply stirring the obtained polymers in 95–98% sulfuric acid at room temperature. Following this, poly(arylene ether ketone)s bearing both carboxyl and sulfonic acid groups were prepared through a hydrolysis reaction of the ester groups on the above sulfonated polymers. The properties, including thermal, oxidative and dimensional stability, water absorption, mechanical properties, proton conductivity and methanol crossover of both sulfonated and sulfonated/carboxylated polymers were well investigated. It was found that some membranes exhibited good properties for proton exchange membranes.
HicknerMAGhassemiHKimYSEinslaBRMcGrathJE. Alternative polymer systems for proton exchange membranes (PEMs). Chem Rev2004; 104: 4587–4612.
2.
LiuBJKimDSGuiverMD. Membrane Technology: Membranes for Energy Conversion, Peinemann KV and Nunes SP (eds.). New York: Wiley -VCH, 2008.
3.
ChenYMengYHayAS. Novel synthesis of sulfonated poly(phthalazinone ether ketone) used as a proton exchange membrane via N−C coupling reaction. Macromolecules2005; 38: 3564–3566.
4.
TsangEMWZhangZBShiZQSobolevaTHoldcroftS. Considerations of macromolecular structure in the design of proton conducting polymer membranes: graft versus diblock polyelectrolytes. J Am Chem Soc2007; 129: 15106–15107.
5.
XuKChanthadCGadinskiMRHicknerMAWangQ. Acid-functionalized polysilsesquioxane−nafion composite membranes with high proton conductivity and enhanced selectivity. Appl Mat Interfaces2009; 11: 2573–2579.
6.
YangYHoldcroftS. Synthetic strategies for controlling the morphology of proton conducting polymer membranes. Fuel Cells2005; 5: 171–186.
7.
HigashiharaTMatsumotoKUedaM. Sulfonated aromatic hydrocarbon polymers as proton exchange membranes for fuel cells. Polymer2009; 50: 5341–5357.
8.
GuoMMLiuBJLiLLiuCWangLFJiangZH. Preparation of sulfonated poly(ether ether ketone)s containing amino groups/epoxy resin composite membranes and their in situ crosslinking for application in fuel cells. J Power Sources2010; 195: 11–20.
9.
LiuBJHuWChenCH. Soluble aromatic poly(ether ketone)s with a pendant 3,5-ditrifluoromethylphenyl group. Polymer2004; 45: 3241–3247.
10.
PerngLH. Thermal cracking characteristics of PEEK under different environments by the TG/FTIR technique. J Polym Sci Part A Polym Chem1999; 37: 4582–4590.
EinslaMLKimYSHawleyM. Toward improved conductivity of sulfonated aromatic proton exchange membranes at low relative humidity. Chem Mater2008; 20: 5636–5642.
13.
LiuBJRobertsonGPKimDSGuiverMDHuWJiangZH. Aromatic poly(ether ketone)s with pendant sulfonic acid phenyl groups prepared by a mild sulfonation method for proton exchange membranes. Macromolecules2007; 40: 1934–1944.
14.
MaXHZhangCJXiaoGYYanDYSunGM. Synthesis and characterization of sulfonated poly(phthalazinone ether phosphine oxide)s by direct polycondensation for proton exchange membranes. J Polym Sci Part A Polym Chem2008; 46: 1758–1769.
GaoYRobertsonGPKimYS. Synthesis of homo- and copoly(arylene bicarbazole)s via nucleophilic substitution polycondensation reactions of NH groups with activated dihalides. Macromolecules2007; 40: 4744–4746.
18.
PangJHZhangHBLiXFJiangZH. Novel wholly aromatic sulfonated poly(arylene ether) copolymers containing sulfonic acid groups on the pendants for proton exchange membrane materials. Macromolecules2007; 40: 9345–9442.
KimDSShinKHParkHBChungYSNamSYLeeYM. Synthesis and characterization of sulfonated poly(arylene ether sulfone)copolymers containing carboxyl groups for direct methanol fuel cells. J Membrane Sci2006; 278: 428–436.
