4,4 -Difluorodiphenyl sulfone

An AB monomer, 2-(4-hydroxyphenyl)-3-phenyl-6-fluoroquinoxaline [17], was prepared from the reaction of 4-hydroxybenzil and l,2-diamino-4-fluorobenzene and subsequently polymerized under aromatic nucleophilic displacement conditions in NMP. The resultant polymer exhibited an intrinsic viscosity of 1.23 dL/g, a Tg of 247 °C and thin film tensile strength and modulus at room temperature of 107 Mpa and 3.2 GPa, respectively [17]. The same AB monomer was also copolymerized with hydroquinone and 4,4 -difluorodiphenyl sulfone to yield a series of copolymers with interesting properties [17]. The same AB monomer was prepared and polymerized by other researchers to yield a polymer with an intrinsic viscosity of 0.65 dL/g and a Tg of 255 °C [18]. 

The poly( arylene ether sulfones) were prepared as previously described (10,14,24). Toluene/DMAC was the usual solvent system used. The more reactive 4,4 -difluorodiphenyl sulfone was used in reactions with the relatively acidic 4,4 -sulfonyldiphenol. 

Poly(biphenyl ether sulfone)s can be prepared, with carbonates or with the alkali metal hydroxides as activators. In the carbonate method, the poly(sulfone)s are prepared by the reaction of equimolar amounts of dihydroxy aromatic compounds and dihalodiaryl sulfones. Dihydroxy aromatic compounds are BP, 4,4 -dihydroxydiphenyl sulfone, hydroquinone, bisphenol A. Dihalodiaryl sulfones, are 4,4 -dichlorodiphenyl sulfone or 4,4 -difluorodiphenyl sulfone. 0.5 to about 1.0 mole of an alkali metal carbonate per mole of hydroxyl group is added. The condensation is conducted as azeotropic condensation, at a temperature of 210-300°C up to 15 hours. 

In a variant of the procedure, earlier, it has been proposed to add 4,4 -dichlorodiphenyl sulfone not in equimolar quantities, but in a slight excess. When the reaction is essentially complete, 4,4 -difluorodiphenyl sulfone may be added. 

The effects of the 4,4 -difluorodiphenyl sulfone depend on the proportion added. At not more than about 0.5% molar, relative to the bis-(chloro-... 

Essentially the same phenomenon was observed in the polycondensation of 4-chlorobenzenesulfinate or 4-fluorobenzenesulfinate. The addition of a small amount of 4,4 -difluorodiphenyl sulfone greatly increases the yield of polymer. It was explicitly stated that 4,4 -difluorodiphenyl sulfone may act as an initiator for a chain-growth polycondensation. The reaction scheme is shown in Figure 7.3. 

In poly(ether sulfone)s that are prepared by polycondensation of silyl-ated 4-terf-butylcatechol and 4,4 -difluorodiphenyl sulfone, macrocyclic polymers were obtained to some extent. The cyclic polymers were detected by means of matrix-assisted laser desorption ionization time of flight (MALDI-TOF) mass spectrometry. 

Sidfonated poly(thiophenylene sulfones) were prepared by the interaction of sulfonated 4,4 -difluorodiphenyl sulfone with 4,4 -dimercaptobenzopheno-ne [116]. Not only homopolymers, but also copolymers were obtained. In the latter case, the fraction of sulfonated 4,4 -difluorodiphenyl sulfone was replaced with nonsulfonated monomers. 

Bis (ethylphenylcarbamodithioato-S,S )-(T-4)-zinc. See Zinc ethylphenyidithiocarbamate Bis(N-ethyl-N-phenyl) urea. See N,N -Diethyl-N,N -diphenylurea Bis (ethyixanthic) disulfide Bis (ethyixanthogen) disulfide. See Diethyl xanthogen disulfide Bis (4-fluorophenyl) sulfone. See 4,4 -Difluorodiphenyl sulfone 1,4-Bis (1-formamido-2,2,2-trichloroethyl) piperazine N,N -Bis (1-formamido-2,2,2-trichloroethyl) piperazine. SeeTriforine Bis (2-furfuryl) disulfide. See Difurfuryl disulfide... 

Chlorodifluoroethane Difluorochloromethane. See Chlorodifluoromethane Difluorodibromomethane. See Dibromodifluoromethane Difluorodichloromethane. See Dichlorodifluoromethane 4,4 -Difluorodiphenyl sulfone CAS 383-29-9 EINECS/ELINCS 206-847-4 Synonyms Bis (4-fluorophenyl) sulfone 4-Fluorophenyl sulfone... 

Fluorophenyl sulfone. See 4,4 -Difluorodiphenyl sulfone Fluorophlogopite. See Fluorphlogopite Fluorosalan... 

Difluorodiphenyl sulfone 206-864-7 Nalidixic acid 206-969-8 Capsaicin 206-988-1 Sodium palmitate 206-990-2... 

Other polysulfone membranes for DMFC were prepared by sulfonation of commercial polyethersulfone with Cardo group (sPES-C) [473] (Fig. 6.9), by sulfonation of a commercial poysulfone and the use of silica as a filler [474], by "click" cycloaddition of alkyne sulphonate to polysulfone containing azide moieties and crosslinked with 1,7-octadiyne [475], and by polycondensation of 4,4 -difluorodiphenyl sulfone (DFDPS) and l,3-bis(4-fluorobenzoyl)benzene,6,7-dihydroxy-2-naphtha lene sulfonate with bisphenol [476]. Commercial poly(phtalazinone ether sulfone ketone (PPESK) [477], Udel (Solvay) polysulfone [478-480], and Lasuf Lati SPA) polysulfone [481] were sulfonated to prepare membranes for DMFC. Relative selectivity larger than 7 have been obtained with some of these membranes [477,478], as indicated in Fig. 6.37. 

Figure 7.4 Synthesis of 3,3, 5,5 -tetra(4"-meth-oxyphenyl)-4,4 -difluorodiphenyl sulfone [22],...

The effects of the 4,4 -difluorodiphenyl sulfone depend on the proportion added. At not more than about 0.5% molar, relative to the bis-(chloroaryl)-sulfone, it essentially prevents further polycondensation by reacting with hydroxy salt on the polymer chain. At 0.5-5%, molar stabilization or a decrease in the molecular weight of the polymer occurs. If the polymer molecular weight is greater than desired, the addition of a suitable proportion of 4,4 -difluorodiphenyl sulfone can decrease it to the desired value [27]. 

PAES with pendant sulfonated aliphatic side chains have been prepared by a nucleophilic substitution polycondensation and sulfoakylation reaction [94]. 3, 3-Bis(4-hydroxyphenyl)-l-isobenzopyrrolidone and 4,4 -difluorodiphenyl sulfone or 3,3, 4,4 -tefrafluoro-diphenylsulfone were used as monomers. Membranes formed from these polymers displayed a low water uptake and swelling ratio both at ambient temperature... 

Quatemized PAES with up to two pendant quaternary ammonium groups have been prepared by a cesium carbonate mediated direct aromatic nucleophihc subshtuhon polycondensahon of 2,2 -dimethylaminemethylene-4,4 -biphenol, 4,4 -biphenol, and 4,4 -difluorodiphenyl sulfone, followed by the reaction with iodomethane [96]. These types of ionomers are more stable than some fluorinated PAES ionomers under highly basic conditions. 

Also, multi-block PAES copolymers with pendant quaternary ammonium groups have been synthesized [114]. One block is made from 3,3, 5,5 -tetramethyl-4,4 -biphenol and 4,4 -difluorodiphenyl sulfone. The other block is made from bis(4-hydroxyphenol) sulfone and 4,4 -difluorodiphenyl sulfone. After combining the two blocks, the pendant methyl groups in the 3,3, 5,5 -tetramethyl-4,4 -biphenol moiety are bro-momethylated with A-bromosuccinimide and finally quaternized. The materials are used for alkaline fuel cells. 

Zhao et al. synthesized a series of sulfonated poly(benzoxazole thioether sulfone)s (SPTESBO-XX) by varying the molar concentration of sulfonated monomer, disodium 3,3 -disulfonated-4,4 -difluorodiphenyl sulfone (SDCDPS) with 2,2 -bis[2-(4-fluorophenyl) benzoxazol-6-yl] hexa-fluoropropane (6BO) and 4,4 -thiobisbenzenethiol (TBBT) (Figure 5.68) [108]. They also prepared another series (SPTESBO-HFB-XX) by incorporating... 

Some compounds gave abnormal results thus fluorobenzene with neat chlorosulfonic acid (40 C) only gave 4,4 -difluorodiphenyl sulfone. On the other hand, treatment of fluorobenzene with the reagent in chloroform solution afforded some /7-fluorobenzenesulfonyl chloride while m-difluorobenzene reacted with excess reagent (30-40 C, 3 hours) to give 2,4-difluorobenzenesulfonyl chloride (98.6% yield). ... 

Meanwhile, most commercial polysulfones (PSU) and poly(ether sulfone)s (PES) are obtained from conversion of suitable aromatic dihalides with bisphenols by nucleophiUc displacement polycondensation (Fig. 19B). Generally, 4,4 -dichlorodiphenyl suUbne (DCDPS) is reacted with alkali salts of bisphenols [92,93]. The reaction is carried out in solution using hT-methyl-2-pyrrolidone (NMP), N,N-dimethyl acetamide (DMAc), or dimethyl sulfoxide (DMSO) as the solvent. Occasionally, the more reactive, but also more expensive, 4,4 -difluorodiphenyl sulfone might be used for experimental purposes. Usually, the electronegativity of the sulfone Unkage is sufficient to increase the reactivity of the aromatic chloride in DCDPS (Fig. 19). 

Fig. 24 Synthesis of A sulfonated 4,4 -difluorodiphenyl sulfone and B 3,3 -sulfonyl-fcis-(6-hydroxybenzene sulfonic acid) (sulfonated bisphenol S)...

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