151173-25-0Relevant articles and documents
Poly(phenylene) block copolymers bearing tri-sulfonated aromatic pendant groups for polymer electrolyte fuel cell applications
Chen, Shouwen,Hara, Ryousuke,Chen, Kangcheng,Zhang, Xuan,Endo, Nobutaka,Higa, Mitsuru,Okamoto, Ken-Ichi,Wang, Lianjun
, p. 8178 - 8189 (2013)
Novel poly(tri-sulfonated phenylene)-block-poly(arylene ether sulfone) copolymers (PTSP-b-PAESs) were synthesized by Ni(0)-catalyzed copolymerization of 2,5-dichloro-3′-sulfo-4′-((2,4-disulfo)phenoxy)-benzophenone and chlorobenzophenone-endcapped oligo(arylene ether sulfone). Their physical properties, morphology and polymer electrolyte fuel cell (PEFC) performance were investigated compared to those of poly(mono-sulfonated phenylene)-block- poly(arylene ether sulfone) and the corresponding random copolymers. They had a low ion exchange capacity (IEC) of 1.1-1.2 meq. g-1 and showed very low water uptake and in-plane dimensional change in water. They exhibited a more well-defined microphase-separated structure composed of hydrophilic and hydrophobic domains, where the hydrophilic domains were well-connected to each other to form the channels for proton conduction, than the mono-sulfonated one. This led to the relatively high proton conductivity under low relative humidities. The corresponding random copolymers exhibited a homogeneous morphology and much lower proton conductivity in spite of a high IEC of 2.0-2.1 meq. g-1. Even under the low humidification of 30% RH at 90°C and 0.2 MPa, they exhibited high PEFC performance and durability; for example, a cell voltage of 0.69 V at a load current density of 0.5 A cm-2 and a maximum output of 0.73 W cm-2, which was comparable to that of the mono-sulfonated one with a much higher IEC of 1.8 meq. g-1 and much higher than those of the corresponding random copolymers. PTSP-b-PAESs have high potential as polymer electrolyte membranes for fuel cell applications.
Considerations of polymerization method and molecular weight for proton-conducting poly(p-phenylene) derivatives
Tonozuka, Isao,Yoshida, Miru,Kaneko, Keiichi,Takeoka, Yuko,Rikukawa, Masahiro
, p. 6020 - 6028 (2011)
Ni(0)-catalyzed coupling polymerization of 2,5-dichloro-4′- phenoxybenzophenone was investigated by varying the ligand and coligand, temperature, reaction time, and solvent. The weight-average molecular weight (Mw) of poly(4-phenoxybenzoyl-1,4-phenylene)s (PPBPs) could be controlled by the polymerization conditions and reached a maximum of 4.4 × 105 g mol-1. Sulfonated PPBPs (S-PPBPs) with various Mws were prepared with sulfuric acid to study the effect of molecular weight on the chemical and electrical properties of PPBP-based electrolytes. The strong molecular interactions in S-PPBP provided an ion exchange capacity of 2.9 meq g-1 without loss of high mechanical properties. High molecular weight S-PPBPs had more desirable properties for fuel cell applications. While the swelling ratios and hydration numbers of S-PPBPs decreased with increasing molecular weight, the mechanical strength, proton conductivity, and fuel cell performance increased. S-PPBP also showed anisotropic behavior in the swelling and proton conductivity; such behavior is caused by the rigid-rod nature and the liquid-crystal structure.
Synthesis and investigation of sulfonated poly(: P -phenylene)-based ionomers with precisely controlled ion exchange capacity for use as polymer electrolyte membranes
Rikukawa, Masahiro,Takahashi, Satoshi,Takeoka, Yuko,Yoshida-Hirahara, Miru,Yoshizawa-Fujita, Masahiro
, p. 12810 - 12822 (2020)
To achieve precise control of sulfonated polymer structures, a series of poly(p-phenylene)-based ionomers with well-controlled ion exchange capacities (IECs) were synthesised via a three-step technique: (1) preceding sulfonation of the monomer with a protecting group, (2) nickel(0) catalysed coupling polymerisation, and (3) cleavage of the protecting group of the polymers. 2,2-Dimethylpropyl-4-[4-(2,5-dichlorobenzoyl)phenoxy]benzenesulfonate (NS-DPBP) was synthesised as the preceding sulfonated monomer by treatment with chlorosulfuric acid and neopentyl alcohol. NS-DPBP was readily soluble in various organic solvents and stable during the nickel(0) catalysed coupling reaction. Sulfonated poly(4-phenoxybenzoyl-1,4-phenylene) (S-PPBP) homopolymer and seven types of random copolymers (S-PPBP-co-PPBP) with different IECs were obtained by varying the stoichiometry of NS-DPBP. The IECs and weight average molecular weights (Mws) of ionomers were in the range of 0.41-2.84 meq. g-1 and 143 000-465 000 g mol-1, respectively. The water uptake, proton conductivities, and water diffusion properties of ionomers exhibited a strong IEC dependence. Upon increasing the IEC of S-PPBP-co-PPBPs from 0.86 to 2.40 meq. g-1, the conductivities increased from 6.9 × 10-6 S cm-1 to 1.8 × 10-1 S cm-1 at 90% RH. S-PPBP and S-PPBP-co-PPBP (4 : 1) with IEC values >2.40 meq. g-1 exhibited fast water diffusion (1.6 × 10-11 to 8.0 × 10-10 m2 s-1), and were comparable to commercial perfluorosulfuric acid polymers. When fully hydrated, the maximum power density and the limiting current density of membrane electrode assemblies (MEAs) prepared with S-PPBP-co-PPBP (4 : 1) were 712 mW cm-2 and 1840 mA cm-2, respectively.
One-pot preparation of 2,5-dichloro-4'-phenyloxybenzophenone
Davis, Matthew C.,Groshens, Thomas J.
experimental part, p. 255 - 261 (2011/03/20)
Friedel-Crafts-type acylation of phenyl ether with 2,5-dichlorobenzoic acid could be accomplished in a single step using trifluoroacetic anhydride and phosphoric acid. The method gave a greater yield (78%) than the conventional two-step process (71%) of acid chloride generation followed by aluminum trichloride-mediated acylation. Copyright Taylor & Francis Group, LLC.
Synthesis and properties of sulfonated copoly(p-phenylene)s containing aliphatic alkyl pendant for fuel cell applications
Seesukphronrarak, Surasak,Ohira, Kayo,Kidena, Koh,Takimoto, Naohiko,Kuroda, Carlos Seiti,Ohira, Akihiro
experimental part, p. 623 - 631 (2011/02/16)
A series of novel copoly(p-phenylene)s (PPs) containing an alkyl pendant were successfully synthesized via Ni(0)-catalyzed coupling polymerization. Sulfonated copolymers (SPPs) were achieved by postsulfonation from concentrated H2SO4. SPPs showed good solubility in polar aprotic solvents and gave flexible, tough, and transparent free-standing films by solvent casting. The ion exchange capacities (IECs) of the membranes ranged from 2.50 to 2.65?meq/g. All SPP membranes displayed proton conductivity similar to or higher than that of Nafion, especially at high relative humidity (>70% RH) (SPP-1: 0.271 Scm-1, SPP-2: 0.284 Scm-1, SPP-3: 0.212?S?cm-1, Nafion: 0.127 Scm-1; at 80?°C and 95% RH). They also exhibited acceptable water uptake in the range of 52-56?vol% at 80?°C with little dimensional change. The gas permeability of the SPP membranes was much lower than that of Nafion 112. Therefore, these materials are promising for fuel cell application.
Halogenated aromatic compound, (co)polymer thereof, and proton-conductive membrane comprising same
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, (2008/06/13)
A halogenated aromatic compound, a polyarylene (co)polymer obtained by the polymerization of such a halogenated aromatic compound as a monomer component, and a proton-conductive membrane made of a sulfonation product of such a (co)polymer are disclosed. T
