Partially fluorinated characterization

As part of an effort to develop high-performance, high-temperature-resistant polymers for microelectronics applications, we also recently described a series of both partially fluorinated and nonfluorinated poly(aryl ether ketone)s containing amide, amide-imide, cyano oxadizole, or pyridazine groups and characterized their thermal and electrical properties.11... 

Schonberger, R, Hein, M. and Kerres, J. 2007. Preparation and characterization of sulfonated partially fluorinated statistical poly(arylene ether sulfone)s and their blends with PBl. Solid State Ionics 178 547-554. 

The mass spectra of several partially fluorinated P-diketonatochromium(iii) complexes have been determined and discussed. Hydroxyhexafluoro-isobutyric acid, H0C(CF3)2C02H (34), acts as a bidentate ligand and forms a tris-octahedral complex with chromium(iii). A new ligand, hydroxy-methylenenorcamphor (61) (HL) has been synthesized and CrL3 has been prepared and characterized. ... 

The chemical nature of the base polymer is an important aspect in membrane development. There has been preference for the thermally stable fluorinated polymers over hydrocarbon polymers. Fluorine-containing polymers, characterized by the presence of carbon-fluorine bonds, are widely used as the base matrices owing to their outstanding chemical and thermal stability, low surface energy, and the ease of modiflcation of various properties by the grafting method. Per fluorinated polymers and partially fluorinated polymers combining hydrocarbon and fluorocarbon structures are excellent candidates as base polymers. For instance, fluorinated FEP has drawn wide attention due to its reasonably good radiation stabiUty [58]. 

Lee HS, Roy A, Lane O, Lee M, McGrath JE. Synthesis and characterization of multiblock copolymers based on hydrophilic disulfonated poly(arylene ether sulfone) and hydrophobic partially fluorinated poly(arylene ether ketone) for fuel cell applications. J Polym Sci Part A Polym Chem 2010 48(l) 214-22. 

A partially fluorinated polymer, also soluble in polar solvent, is PVDF. It is characterized by high performance, chemical resistance, good thermal stability, and resistance to UV light and oxidant attack (Chin et al., 2006). PVDF membranes have been used primarily in the construction of submerged modules, widely used in bioreactors because of their lower costs with respect to other types of photocatalytic membranes (Sopajaree et al., 1999 Chin, Lim, Chiang, Fane, 2007 Jia et al., 2006, Fu, Ji, Wang, Jin, An, 2006). 

Li Y, Roy A, Badami AS, Hill M, Yang J, Dunn S, McGrath JE (2007) Synthesis and characterization of partially fluorinated hydrophobic-hydrophilic multiblock copolymers containing sulfonate groups for proton exchange membrane. J Power Sources 172 30... 

Therefore, in a comparative study, different nonfluorinated and partially fluorinated sulfonated aromatic polymers were synthesized and characterized in terms of chemical and thermal stabilities. It was found that SO3H groups introduced in the electron-deficient sections of the aromatic polymer main chains were much more stable against splitting-off than SO3H groups pendent to electron-rich sections of the polymer backbones [29]. One of the most stable polymers of this series was a polymer prepared by polycondensation of decafluorobiphenyl and bisphenol (AF), followed by sulfonation with... 

Kerres J, Schonberger F, Chromik A et al (2008) Partially fluorinated arylene polyethers and their ternary blend membranes with PBI and H3PO4 Part I. Synthesis and characterization of polymers and binary blend membranes. Fuel Cells 8 175-187... 

This section seeks to report the preparation and characterization of PEMs based on partially fluorinated aromatic polymers. In the past few decades, attention has focused on the preparation of new fluorinated monomers and aromatic fluoropolymers. This topic was recently reviewed [70], summarizing the characteristic effects of the aromatic group on the physicochemical properties (e.g., Tg and the thermostability of the obtained polymers). 

Partial substitution of fluorine for oxygen in VO2 and V 2O5 has been achieved by treating these oxides with aqueous hydrofluoric acid under pressure. The new phases of composition V02. xFjc (for 0 < x < 0.2) and V205 Fj( (for 0 < X < 0.025) were obtained and characterized by X-ray diffraction studies. The oxide-fluoride bronze K0.25VO0.75F2.25 has been prepared from the high-temperature reaction of KVO3 and VF3 and the unit cell parameters have been determined. 

Catalytic quantities of HF or FSO3H decrease the temperature required for fiuorination of graphite -250°C is sufficient at a HF partial pressure of 200 torr . Catalytic fiuorination of graphite proceeds via ionic or n charge-transfer intermediates which are characterized by high mobility of the intercalant. In contrast, there is no evidence for mobile fluorine in (CFJ Silver fluoride , LiF and CuFj have also been used as fiuorination catalysts. 

Barnes and coworkers had prepared A-triisopropylsilyl-3-fluoropyrrole 53 from the corresponding bromo derivative but did not report the isolation of the N-unsubstituted parent 52. However, 53 could be desilylated to produce 52, which was used in situ to produce partially p-fluorinated porphyrins and derivatives (Fig. 3.24). Attempts to isolate and purify 52 either from the desilylated crude product or through deprotection of the derived Boc-protected intermediate 54 met with limited success, although sufficient material for characterization was produced... 

Leroy, J. Porhiel, E. Bondon, A. Synthesis and characterization of partially 3-fluorinated 5,10,15,20-tetraphenylporphyrins and some derivatives. Tetrahedron 2002, 58, 6713-6722. 

The word oil is used for an organic phase that is essentially immiscible with water and is thus relatively apolar. It can refer to a hydrocarbon, a partially or totally chlorinated or fluorinated hydrocarbon, single-chain alkane, cyclic or aromatic hydrocarbon, polar monoester such as ethyl oleate, long-chain alcohol such as dodecanol, triglyceride natural oil, or polycyclic cholesterol. The most typical oil phase is, of course, n-alkane, which would be characterized by its length or alkane carbon number (ACN). 

Novel nanoscale discotic liquid crystalline porphyrins 14 with partial alkyl chain perfluorination has been designed and synthesized in our group which exhibits exceptionally enhanced tendency to spontaneously self-assemble into homeotropically ordered nanostructures [107]. The defect-free homeotropically aligned fluorinated porphyrin thin films were fabricated and characterized. In the films thinner than 10 pm in glass cells, it shows strong tendency towards homeotropic... 

There are numerous articles in the literature describing the synthesis and characterization of polymers with their main chains or side groups partially substituted by fluorine atoms. These low-fluorine polymers are usually soluble in common solvents and therefore are not included in this review. Only a few commercial fluoropolymers, which are soluble in uncommon solvents, are reviewed. These polymers include polyvinylidene fluoride, polyperfluoroethers, poly(bis-trifluoroethoxyphosphazenes), and polytrifluoroethylenes, and Kel-F polymer. 

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