Kenji Miyatake

Poly(arylene ether sulfone)-based ionomers containing sulfofluorenyl groups have been synthesized for applications to polymer electrolyte membrane fuel cells (PEMFCs). In order to achieve high proton conductivity and chemical, mechanical, and dimensional stability, the molecular structure of the ionomers has been optimized. Tough, flexible, and transparent membranes were obtained from a series of modified ionomers containing methyl groups with the ion-exchange capacity (IEC) ranging from 1.32 to

Proton exchange membrane fuel cells (PEMFCs) are promising devices for clean power generation in automotive, stationary, and portable applications. Perfluorosulfonic acid (PFSA) ionomers (for example, Nafion) have been the benchmark PEMs; however, several problems, including high gas permeability, low thermal stability, high production cost, and environmental incompatibility, limit the widespread dissemination of PEMFCs. It is believed that fluorine-free PEMs can potentially address all of these

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTNovel Sulfonated Poly(arylene ether): A Proton Conductive Polymer Electrolyte Designed for Fuel CellsKenji Miyatake, Yohei Chikashige, and Masahiro WatanabeView Author Information Clean Energy Research Center, University of Yamanashi, 4 Takeda, Kofu 400-8510, Japan Cite this: Macromolecules 2003, 36, 26, 9691–9693Publication Date (Web):November 27, 2003Publication History Received27 September 2003Revised7 Nove

A series of sulfonated polyimide copolymers (FSPIH-X; X refers to molar percentage of bis(trifluoromethyl)biphenylene content) with X from 0 to 60 mol % were synthesized, of which electrolyte properties were investigated and compared to those of the perfluorinated ionomer (Nafion 112). FSPIH-X membranes are thermally stable with no glass transition temperature observed below the decomposition temperature (280 °C). Oxidative stability of the membranes is improved with an increase in the content o

The polymerization of 2,3,5,6-tetraphenylhydroquinone (or 2,2‘,3,3‘,5,5‘-hexaphenyl-4,4‘-dihydroxybiphenyl) with α,ω-tetrahydroperfluoroalkanediol and decafluorobiphenyl was carried out to synthesize a series of copolymers III (Mw = 49 100−80 900). The copolymers III are composed of arylene ether (10−30 mol %) and fluorinated alkane (90−70 mol %) moieties. The reaction of III with chlorosulfonic acid gave sulfonated polymers IV, which are soluble in polar organic solvents and form flexible and t

Novel sulfonated polyimide copolymers as electrolytes for high-temperature fuel cell applications are reported. A series of sulfonated polyimide copolymers (SPIH-X; X refers to molar percentage of fluorenyl content) containing 0−60 mol % of fluorenyl groups as hydrophobic component were synthesized, of which electrolyte properties were investigated and compared to those of the perfluorinated ionomer (Nafion 112). High-molecular-weight copolymers with good film-forming capability were obtained. T

Novel sulfonated polyimides containing fluorenyl groups show good thermal and oxidative stability as well as a high proton conductivity of 1.67 S cm(-1) at 120 degrees C and 100% RH.

ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTSynthesis of Poly(phenylene sulfide sulfonic acid) via Poly(sulfonium cation) as a Thermostable Proton-Conducting PolymerKenji Miyatake, Hiroyuki Iyotani, Kimihisa Yamamoto, and Eishun TsuchidaView Author Information Department of Polymer Chemistry, Advanced Research Institute for Science and Engineering, Waseda University, Tokyo 169, JapanCite this: Macromolecules 1996, 29, 21, 6969–6971Publication Date (Web)

A series of anion conductive aromatic ionomers, poly(arylene ether)s containing different polymer backbones and quaternized ammonio-substituted fluorenyl groups, were synthesized via nucleophilic substitution polycondensation, chloromethylation, quaternization, and the subsequent ion exchange reactions. The ion exchange capacity (IEC) of the ionomers was controlled to be from 0.68 to 2.54 meq. g−1 by the chloromethylation reaction conditions. The designed chemical structures were well-characteri

Well-designed ammonium-functionalized polymers achieved high performance and durability in hydrazine alkaline fuel cells.

Partially fluorinated aromatic polymer-based anion exchange membranes with propylene side chains exhibit high chemical stability and alkaline fuel cell performance.

For polymer electrolyte fuel cells, proton conducting electrolyte membranes are key materials. This review highlights aromatic polymers containing cardo groups and ionic functions as emerging electrolyte materials. First, the role of biphenyl fluorene groups on sulfonated polyimides is discussed. Discussion then focuses on how to balance proton conductivity and membrane stability with sulfonated poly(arylene ether)s making the most of the bulky cardo groups. Block copolymer structure containing

Abstract A series of novel sulfonated polyimides (equivalent weight per sulfonic acid = 310–744 g/equiv) containing 10–70 mol % 1,5‐naphthylene moieties were synthesized as potential electrolyte materials for high‐temperature polymer electrolyte fuel cells. The polycondensation of 1,4,5,8‐naphthalene tetracarboxylic dianhydride, 4,4′‐diamino‐2,2′‐biphenyldisulfonic acid, and 1,5‐diaminonaphthalene gave the title polymer electrolytes. The polyimide electrolytes were high‐molecular‐weight (number‐

A novel sulfonated polyimide having pendant sulfophenoxypropoxy groups was synthesized, and its electrolyte properties were investigated for fuel-cell applications. A diamine monomer was synthesized from 3,3′-dihydroxybenzidine in four steps, and its polymerization was performed with 1,4,5,8-naphthalenetetracarboxylic dianhydride in the presence of triethylamine and benzoic acid in m-cresol. A flexible, ductile, and self-standing membrane was obtained via casting from an m-cresol solution. Good

The synthesis and characterization of poly(thiophenylenesulfonic acid), a novel class of polyaromatic electrolyte possessing up to 2.0 sulfonic acid groups per phenylene unit (m = 2.0), are described. 4-(Methylsulfinyl)diphenyl sulfide (1) was polymerized in sulfuric acid upon heating (<140 °C) or in the presence of SO3 to yield a sulfonated poly(sulfonium cation) (4), which can be converted to the corresponding sulfonated poly(thiophenylene). The precursor method using the soluble poly(sulfoniu