113939-45-0Relevant articles and documents
Fluorinated aromatic polyether ionomers containing perfluorocyclobutyl as cross-link groups for fuel cell applications
Lee, Kwan-Soo,Jeong, Myung-Hwan,Kim, Young-Jea,Lee, Su-Bin,Lee, Jae-Suk
, p. 1443 - 1453 (2012)
The cross-linkable copolymers (SHQx-TFVys) with varying degrees of sulfonation (DS) from 70 to 95% were prepared from potassium-2,5- dihydroxybenzenesulfonate (SHQ), decafluorobiphenyl (DFBP), and 4-(trifluorovinyloxy)-biphenyl-2,5-diol (TFVOH) as a cross-linkable moiety. To develop a highly stable polymer electrolyte membrane (PEM) for application in polymer electrolyte fuel cells (PEFC)s, cross-linked membranes were prepared by chemical cross-linking. The cross-linked membranes were synthesized by varying the amount of TFVOH (5-30 mol %) in order to achieve desirable PEM properties. The structures of the cross-linkable monomer and polymers were investigated by 1H and 19F NMR and FT-IR spectra. The cross-linked membranes exhibited good glass transition temperature and thermal stability up to 239-271 °C and 290-312 °C, respectively. The crosslinked membranes (DS range 80-95%) exhibited higher proton conductivity(0.098-0.151 S/cm) than Nafion 212 (0.092 S/cm). Moreover, all membranes possessed lower methanol permeability (13-132 × 10-8 cm2/s) compared with Nafion 212 (163 ×10-8 cm2/s) under the same measurement conditions. The H2/O2 single cell performance tests of the cross-linked membranes and Nafion 212 were performed. The CSHQ90-TFV10 exhibited the higher maximum power density (1.053 W/cm2) than that of Nafion 212 (0.844 W/cm2).
Expanding the Scope of Hypervalent Iodine Reagents for Perfluoroalkylation: From Trifluoromethyl to Functionalized Perfluoroethyl
Matouek, Vclav,Vclavk, Ji,Hjek, Peter,Charpentier, Julie,Blastik, Zsfia E.,Pietrasiak, Ewa,Budinsk, Alena,Togni, Antonio,Beier, Petr
, p. 417 - 424 (2016)
A series of new hypervalent iodine reagents based on the 1,3-dihydro-3,3-dimethyl-1,2-benziodoxole and 1,2-benziodoxol-3-(1H)-one scaffolds, which contain a functionalized tetrafluoroethyl group, have been prepared, characterized, and used in synthetic applications. Their corresponding electrophilic fluoroalkylation reactions with various sulfur, oxygen, phosphorus, and carbon-centered nucleophiles afford products that feature a tetrafluoroethylene unit, which connects two functional moieties. A related λ3-iodane that contains a fluorophore was shown to react with a cysteine derivative under mild conditions to give a thiol-tagged product that is stable in the presence of excess thiol. Therefore, these new reagents show a significant potential for applications in chemical biology as tools for fast, irreversible, and selective thiol bioconjugation.
Unexpected reactivity of cyclic perfluorinated iodanes with electrophiles
Gruber, Stefan,Ametamey, Simon M.,Schibli, Roger
, p. 8999 - 9002 (2018)
We have found that cyclic perfluorinated iodanes react with electrophiles (E+ = Br, Cl, F, I) to afford perfluorinated E-RF compounds. This reactivity is unexpected since cyclic perfluorinated iodanes are considered as electrophilic reagents that normally react with nucleophiles (e.g. Nu- = SR, OR) to afford Nu-RF products. The utility of this new transformation is demonstrated for a [18F]CF3CF2-containing compound which was prepared from [18F]XeF2 obtained from cyclotron produced [18F]fluoride.
Postpolymerization of functional organosiloxanes: An Efficient strategy for preparation of low-k material with enhanced thermostability and mechanical properties
Yuan, Chao,Wang, Jiajia,Jin, Kaikai,Diao, Shen,Sun, Jing,Tong, Jiawei,Fang, Qiang
, p. 6311 - 6315 (2014)
A novel functional oligomer (Si-TFVE) with a siloxane backbone and thermally cross-linkable trifluorovinyl ether groups (-OCF=CF2) is reported here. When postpolymerized at high temperature, Si-TFVE converts to an amorphous cross-linked network (Si-PFCB), which shows a dielectric constant of 2.33 and dielectric loss below 2.1 × 10-3 at 30 MHz. Si-PFCB also shows excellent film uniformity with the surface roughness less than 5.79 nm over a 1 μm square area. Moreover, Si-PFCB shows high thermostability with a 5 wt % loss temperature of 472°C and no obvious Tg below 350°C. In regard to the mechanical properties, Si-PFCB has Young's modulus, hardness, and bonding strength with silicon wafer surface of 10.06 GPa, 0.392, and 4.93 GPa, respectively. These results suggest that such oligomer is suitable for utilization in ultralarge scale integration circuits. In addition, this contribution provides a new route to prepare cross-linked organosiloxanes only by heating instead of using catalysts or initiators in the traditional procedures. (Chemical Equation Presented).
Novel fluorinated poly(aryl ether)s derived from 1,2-bis(4-(4-fluorobenzoyl)phenoxy)-hexafluorocyclobutane
Zhou, You,Qing, Feng-Ling
, p. 498 - 502 (2008/12/22)
Two novel poly(aryl ether)s were prepared from 1,2-bis(4-(4-fluorobenzoyl)-phenoxy)-hexafluorocyclobutane and aromatic bisphenols by the aromatic nucleophilic substitution reaction in a polar aprotic solvent. These polymers have good thermal stability up to 341 °C with 10% weight loss in inert atmosphere and good solubility in common organic solvents such as THF, DMAc, DMF and DMSO.
Perfluorocyclobutyl (PFCB) aromatic polyethers: Synthesis and characterization of new sulfonimide containing monomers and fluoropolymers
Ford,DesMarteau,Smith Jr.
, p. 653 - 660 (2007/10/03)
The synthesis and thermal cyclopolymerization of aryl trifluorovinyl ether monomers containing novel sulfonimide acid functionalities are described. The monomers are prepared starting from commercially available 4-bromophenol in five steps. These novel polymers explore a new versatile class of partially fluorinated polymers for potential use in fuel cells and other electrochemical applications.
AROMATIC POLYMERS WITH PENDANT FLUORINATED IONIC GROUPS
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, (2008/06/13)
A class of unsaturated compounds including containing a fluoroether-substituted aromatic ring, polymers, including ionomers, formed therefrom, and processes for forming them. The compositions of the invention have particular suitability for use in electro
Synthesis and Characterization of Phenylphosphine Oxide Containing Perfluorocyclobutyl Aromatic Ether Polymers for Potential Space Applications
Jin, Jianyong,Smith Jr., Dennis W.,Topping, Chris M.,Suresh,Chen, Shengrong,Foulger, Stephen H.,Rice, Norman,Nebo, Jon,Mojazza, Bob H.
, p. 9000 - 9004 (2007/10/03)
A novel class of phenylphosphine oxide (PPO) containing perfluorocyclobutyl (PFCB) polymers has been developed for potential use as multifunctional materials in space environments. The reaction of p-BrArOCF=CF2 (for Ar = phenyl and biphenyl) with tert-butyllithium affords the lithium reagent smoothly below -20 °C. Subsequent substitution with phenylphosphonic dichloride provides the first bis(trifluorovinyl ether) monomers containing the PPO group. Polymerization proceeds thermally above 150 °C to give polymers that exhibit glass transition temperatures of 169 and 224 °C, respectively, and catastrophic weight loss by TGA in N2 and air above 450 °C (10 °C/min). Copolymerization with bis(4,4′-trifluorovinyloxy)biphenyl affords film-forming transparent thermoplastic copolymers with high Tg (>140 °C) and good thermal stability (>450 °C). Initial evaluations with ground-based simulation of atomic oxygen (AO) rich space environments indicate that the PPO group imparts significant space durability to PFCB polymers.
Aromatic monomers with pendant fluoroalkylsulfonate and sulfonimide groups
Feiring, Andrew E.,Wonchoba, Edward R.
, p. 129 - 135 (2007/10/03)
Novel styrene and dimethylisophthalate monomers with pendant lithium fluoroalkylsulfonate or sulfonimide functional groups have been prepared from the corresponding phenolic intermediates. One route involves several steps and uses 1,2-dibromotetrafluoroethane as the key fluorinated intermediate. A second route with fewer steps utilizes a perfluoroalkylsulfonyl-substituted vinyl ether as the source of the fluorinated substituents but affords a product with significantly higher equivalent weight.