Fluorinated poly(arylene ether ketone)s bearing pentafluorostyrene moieties prepared by a modified polycondensation

Ding, Jianfu; Liu, Futian; Li, Mei; Day, M.; Zhou, Ming

doi:10.1002/pola.10504

Cited by 50 publications

(46 citation statements)

References 37 publications

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“…In this regard, see also the GPC analysis of the cyclic fraction in ref. [3] Typical GPC curves are shown in Figure 1 and 5. The small peak on the low molecular weight side at 30.5 min is attributed to the cyclic oligomers.…”

Section: Instrumentationmentioning

confidence: 99%

“…[4][5][6][7][8][9] Even under mild reaction conditions (i.e., at 113 8C) when molecular sieves were used to dehydrate the solution, a shoulder peak associated with branched structures was observed in the GPC curves of the final products. [3,13] In addition, it was also noted that molecular weights obtained were always lower than the designed values due to this side reaction upsetting the 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, CaH 2 has been used as a base to facilitate the formation of the phenolate; an alkali metal fluoride was used as a catalyst.…”

Section: Introductionmentioning

confidence: 99%

“…[16] Therefore, a low boiling, non-polar co-solvent such as toluene has been introduced into the reaction medium to facilitate the removal of water by azeotropic distillation [5][6][7] or by refluxing. [3,13] Unfortunately, this approach reduces the polarity of the polymerization medium and results in a lower selectivity of the reaction. In addition, the azeotropic distillation is not able to completely remove all the water from the reaction solution.…”

Section: Introductionmentioning

confidence: 99%

“…[3] Therefore, in order to further reduce this side reaction, additional modifications to this reaction have been investigated in an attempt to improve the selectivity of the reaction at the para-fluorines.…”

Section: Introductionmentioning

confidence: 99%

“…Fluorinated poly(arylene ether ketone)s (FPAEK) [1][2][3][4][5] are conventionally prepared by the polycondensation of the phenol groups of hexafluorobisphenol A (6F-BPA) with para-fluorines of bis(pentafluorophenyl) ketone (BPK) using a nucleophilic aromatic substitution reaction (S N Ar), [6][7][8][9][10] which has been traditionally used for the preparation of nonfluorinated poly(arylene ether)s. [11,12] The major problem of this reaction when applied to the preparation of FPAEK is the high tendency of a side reaction at the ortho-fluorines of BPK, [3,4] which are activated by the strong electronwithdrawing effect of the ketone group. [10] This side reaction leads to the formation of branched and eventually crosslinked structures.…”

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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Section: Instrumentationmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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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Electrospinning of Manmade and Biopolymer Nanofibers—Progress in Techniques, Materials, and Applications

Agarwal¹,

Greiner²,

Wendorff³

2009

Adv Funct Materials

245

155

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Electrospinning of nanofibers has developed quickly from a laboratory curiosity to a highly versatile method for the preparation of a wide variety of nanofibers, which are of interest from a fundamental as well as a technical point of view. A wide variety of materials has been processed into individual nanofibers or nanofiber mats with very different morphologies. The diverse properties of these nanofibers, based on different physical, chemical, or biological behavior, mean they are of interest for different applications ranging from filtration, antibacterial coatings, drug release formulations, tissue engineering, living membranes, sensors, and so on. A particular advantage of electrospinning is that numerous non‐fiber forming materials can be immobilized by electrospinning in nanofiber nonwovens, even very sensitive biological objects such as virus, bacteria, and cells. The progress made during the last few years in the field of electrospinning is fascinating and is highlighted in this Feature Article, with particular emphasis on results obtained in the authors' research units. Specific areas of importance for the future of electrospinning, and which may open up novel applications, are also highlighted.

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Proton Conducting Phase‐Separated Multiblock Copolymers with Sulfonated Poly(phenylene sulfone) Blocks for Electrochemical Applications: Preparation, Morphology, Hydration Behavior, and Transport

Titvinidze

Kreuer

Schuster

et al. 2012

Adv Funct Materials

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A family of multiblock copolymers consisting of alternating fully sulfonated hydrophilic poly(phenylene sulfone) and hydrophobic poly(phenylene ether sulfone) segments are prepared and characterized. The multiblock copolymers are formed by the coupling of preformed hydrophilic and hydrophobic blocks using a specially designed coupling agent. The block lengths (degree of polymerization) of both segment types were varied in order to control the ion exchange capacity. Solution cast films show spontaneous nanophase separation leading to distinct bicontinuous morphologies with correlation lengths around 15 nm. The hydrophobic phase gives the membranes their advantageous viscoelastic properties even at high temperatures under both wet and dry conditions, while proton conductivity takes place within the hydrophilic phase. Since the properties of fully sulfonated poly (phenylene sulfone)s are locally preserved within the hydrophilic domain, the membranes show very high proton conductivity and high hydrolytic stability. The very high degree of water dispersion within the hydrophilic domains leads to very low electro‐osmotic water drag. Because of their superior transport and stability properties these multiblock copolymers have a great potential for use as a substitute for perfluorosulfonic acid membranes which are used as separator materials in electrochemical applications such as polymer electrolyte membrane (PEM) fuel cells and redox flow batteries.

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Fluorinated poly(arylene ether ketone)s bearing pentafluorostyrene moieties prepared by a modified polycondensation

Cited by 50 publications

References 37 publications

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

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

Electrospinning of Manmade and Biopolymer Nanofibers—Progress in Techniques, Materials, and Applications

Proton Conducting Phase‐Separated Multiblock Copolymers with Sulfonated Poly(phenylene sulfone) Blocks for Electrochemical Applications: Preparation, Morphology, Hydration Behavior, and Transport

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Fluorinated poly(arylene ether ketone)s bearing pentafluorostyrene moieties prepared by a modified polycondensation

Cited by 50 publications

References 37 publications

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

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

Electrospinning of Manmade and Biopolymer Nanofibers—Progress in Techniques, Materials, and Applications

Proton Conducting Phase‐Separated Multiblock Copolymers with Sulfonated Poly(phenylene sulfone) Blocks for Electrochemical Applications: Preparation, Morphology, Hydration Behavior, and Transport

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

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