Cesium fluoride-mediated synthesis of aromatic polysulfides from aromatic dithiols and activated aromatic dihalides

Imai, Yoshio; Yamanaka, Kazuhiro; Ishikawa, Hironobu; Kakimoto, Masa–aki

doi:10.1002/(sici)1521-3935(19990101)200:1<95::aid-macp95>3.0.co;2-m

Cited by 17 publications

(6 citation statements)

References 7 publications

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“…The polycondensation was conducted under mild reaction conditions in DMAc using CsF or KF as a base to convert the hydroxyl group to the alkoxide anion for activating the reaction with DPSO. As illustrated in Scheme 2, in the reaction, CsF or KF also combines with HF, which is produced from the reaction as a byproduct, to form a CsHF 2 or KHF 2 complex that precipitates out of the solution, [7][8][9] allowing the reaction to go to completion, generating a high molecular weight polymer.…”

Section: Resultsmentioning

confidence: 99%

Highly Fluorinated Poly(arylene alkylene ether sulfone)s: Synthesis and Thermal Properties

Ding

Day

et al. 2007

Macromolecules

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Highly fluorinated poly(arylene alkylene ether sulfone)s: synthesis and thermal properties Ding, Jianfu; Du, Xiaomei; Day, M.; Jiang, Jiaren; Callender, C.; Stupak, Jacek Process and EnVironmental Technology, National Research Council of Canada, 1200 Montreal Road, Ottawa, Ontario, Canada K1A 0R6; Communications Research Centre Canada, Ottawa, Ontario, Canada K2H 8S2; and Institute for Biological Sciences, National Research Council of Canada, 100 Sussex DriVe, Ottawa, Ontario, Canada K1A 0R6 ReceiVed January 3, 2007; ReVised Manuscript ReceiVed February 28, 2007 ABSTRACT: A simple procedure has been developed for the preparation of highly fluorinated poly(arylene alkylene ether sulfone)s using a nucleophilic polycondesation reaction of decafluorodiphenyl sulfone (DPSO) with a series of fluorinated linear or branched alkylene diols containing 4-12 carbon atoms. The reactions are activated using cesium fluoride (CsF) or potassium fluoride (KF) as a base in N,N-dimethylacetamide (DMAc) at room temperature and are completed in a few hours or a few days, respectively. Polymers with numberaverage molecular weights (M n ) around 50 000 Da have been prepared. A broad molecular weight distribution and a low dependence of the reaction rate on temperature are observed and attributed to the heterogeneous nature of the reactions. Because of low solubility, CsF and KF exist in the reaction solution mainly in the form of solid particles, and the adsorption of the polymer on the surface of the particles hinders the diffusion of CsF and KF from solid into solution. This effect causes the polymers close to the solid surface to have greater growth rates and higher molecular weights than those in solution. Polymers with linear alkylene spacers display a marked tendency to crystallize, which increases with the length of the alkylene spacer. In fact, the polymer with the longest alkylene spacers (P12C F SO) crystallizes during the polymerization reaction, preventing the polymer chains from growing, resulting in a low molecular weight (M n < 8000 Da). Raising the reaction temperature to 70°C slightly decreases the crystallization tendency and allows the M n to increase to 17 000 Da. The crystallization of P12C F SO is fast enough to be completed during a quenching process induced by immersing the molten sample in liquid nitrogen. However, the polymer with branched alkylene spacers does not show any crystalline structure even when annealed at a temperature slightly higher than its glass transition temperature (T g ). A secondary crystal peak is also found in the DSC curves of the crystalline polymers with linear alkylene spacers. The position of this peak can be shifted to higher temperatures by annealing and has been attributed to incomplete crystallites formed between the primary lamellar crystals.

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Section: Resultsmentioning

confidence: 99%

Highly Fluorinated Poly(arylene alkylene ether sulfone)s: Synthesis and Thermal Properties

Ding

Day

et al. 2007

Macromolecules

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“…This reaction represents a completely different mechanism to that associated with the chain degradation of non-fluorinated polyether ketones and sulfones, [14][15][16][17][18][19][20] where the center of the degradation is the ether group. Clearly in the case of the fluorinated polymers, the ketone groups are more sensitive to nucleophilic attack than ether groups.…”

Section: Highly Fluorinated Poly(arylene Ether Ketone) Prepared By a mentioning

confidence: 99%

“…The presence of trace amounts of water in association with fluoride ions produced during the reaction in the solution will cause serious polymer degradations by side reactions such as hydrolysis and chain scission. [17][18][19][20] It has been reported that the introduction of calcium or magnesium carbonates into the reaction associated with an alkali metal carbonate facilitates the polycondensation. [21][22][23][24][25] Very high molecular weight poly(arylene ether)s have been synthesized when a mixture of calcium carbonate and a small amount of potassium carbonate is used, whereas only low molecular weight polymers are produced using potassium carbonate alone.…”

Section: Introductionmentioning

confidence: 99%

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Highly Fluorinated Poly(arylene ether ketone) Prepared by a CaH₂‐Mediated Polycondensation Reaction

Ding

Day

Robertson

et al. 2004

Macro Chemistry & Physics

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Summary: A new reaction procedure has been developed for the polycondensation of hexafluorobisphenol A (6F‐BPA) with bis(pentafluorophenyl) ketone (BPK) in dimethylacetamide (DMAc). In this reaction, CaH2 has been used as a base to facilitate the formation of the phenolate; an alkali metal fluoride was used as a catalyst. Unlike the conventional polycondensation reactions, this procedure avoided producing water during the reaction, and hence, azeotropic distillation with the assistant of a low‐polar co‐solvent is not required. This improvement maintains the high polarity of the reaction medium; consequently, the selectivity of the reaction at the para‐position of BPK is significantly enhanced and polymers with high molecular weights ($\overline M _{\rm n}$ ca. 30 000 Da) can be obtained with very low branching contents (less than 3 mol‐%) and free of any cross‐linked gel particles. In addition to avoiding the formation of water in the reaction, the use of CaH2 also reduced the concentration of the fluoride ion in the solution. These effects minimize chain degradation reactions such as hydrolysis. The use of CaO instead of CaH2 for this reaction produces similar effects. In the case of CaO, traces of water can be introduced into the reaction. The presence of trace amounts of water increases the polycondensation rate, probably due to the enhanced ionization of the phenolate. However, it also causes a hydrolysis of polymer chains, resulting in the elimination of the ketone group in the polymer backbone. Fortunately, this side reaction is highly water and temperature dependent, and can be efficiently prevented by using CaH2 or conducting the reaction at a lower temperature (<65 °C).CaH2‐mediated polycondensation for the preparation of highly fluorinated poly(arylene ether ketone).imageCaH2‐mediated polycondensation for the preparation of highly fluorinated poly(arylene ether ketone).

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“…The dichloroketones can be good monomers if the nucleophilicity of the coreactant is higher than that of the phenol. It has been reported that high molecular weight poly(thioetherketone)s (PTEKs) 10,11 or poly(thioether-sulfone)s 12,13 have been obtained when highly nucleophilic thiophenol derivatives were used as monomers with a dichloroketone or dichlorosulfone, respectively. However, PTEKs have been paid much less attention.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Properties of Novel Aromatic Poly(thioether−ketone)s as Sulfur-Containing High-Performance Polymers

2001

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Novel aromatic poly(thioether-ketone)s (PTEKs) bearing the 2,6-dimethyl-1,5-naphthylene units were synthesized by the polycondensation of aromatic dihaloketones and aromatic dithiols in the presence of K 2CO3. PTEKs with molecular weight (Mn ∼ 65 000, Mw ∼ 350 000) were obtained in quantitative yields. The molecular weights and yields of PTEKs obtained from aromatic dichloroketone and aromatic dithiols were much higher than those of the corresponding poly(ether-ketone)s (PEKMNs) obtained from aromatic dichloroketone and biphenols and were nearly the same as those of PTEKs obtained from aromatic difluoroketone and aromatic dithiols. The effect of reaction conditions on yield and molecular weight of PTEKs was investigated. The PTEKs had high solubility in ordinary organic solvents. Flexible, transparent, and strong films were cast from CHCl 3 solution. PTEK-1 and PTEK-2 had high glass transition temperatures (Tg; PTEK-1 245°C, PTEK-2 215°C) and 5% weight loss temperatures (Td5; PTEK-1 435°C, PTEK-2 436°C).

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Cesium fluoride-mediated synthesis of aromatic polysulfides from aromatic dithiols and activated aromatic dihalides

Cited by 17 publications

References 7 publications

Highly Fluorinated Poly(arylene alkylene ether sulfone)s: Synthesis and Thermal Properties

Highly Fluorinated Poly(arylene alkylene ether sulfone)s: Synthesis and Thermal Properties

Highly Fluorinated Poly(arylene ether ketone) Prepared by a CaH₂‐Mediated Polycondensation Reaction

Synthesis and Properties of Novel Aromatic Poly(thioether−ketone)s as Sulfur-Containing High-Performance Polymers

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Cesium fluoride-mediated synthesis of aromatic polysulfides from aromatic dithiols and activated aromatic dihalides

Cited by 17 publications

References 7 publications

Highly Fluorinated Poly(arylene alkylene ether sulfone)s: Synthesis and Thermal Properties

Highly Fluorinated Poly(arylene alkylene ether sulfone)s: Synthesis and Thermal Properties

Highly Fluorinated Poly(arylene ether ketone) Prepared by a CaH2‐Mediated Polycondensation Reaction

Synthesis and Properties of Novel Aromatic Poly(thioether−ketone)s as Sulfur-Containing High-Performance Polymers

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Highly Fluorinated Poly(arylene ether ketone) Prepared by a CaH₂‐Mediated Polycondensation Reaction