Synthesis of poly(arylene ether ketones) with terminal phenolic groups

Poly(arylene ether ketones) with preset molecular weights (reduced viscosity from 0. 2 to 0.82 dL g^–1) containing terminal phenolic groups were synthesized by the reactions of 4,4-difluorobenzophenone with bisphenol A or phenolphthalein in the presence of K₂CO₃ in N,N-dimethylacetamide. The influence of an excess of bisphenols on the molecular weights of the polymers obtained was studied. The structures of the polymers were confirmed by ¹H NMR spectroscopy. The molecular weight distributions of the polymers were determined.Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1958–1961, September, 2004.     

Synthesis,isolation, characterization,and properties of small-size aromatic macrocycles for poly(arylene ether ketone)s

A series of macrocyclic arylene ether ketone oligomers from 4,4′-difluorobenzophenone, 2,4′-difluorobenzophenone and 1,3-bis(4′-fluorobenzoyl)benzene were prepared via aromatic nucleophilic substitution according to the pseudo-high dilution principle. Small-size aromatic macrocycles were isolated by silica gel column chromatography with cyclohexane/ethyl acetate as eluent. The chemical structures of these small-size macrocycles were characterized by matrix-assisted laser desorption ionization–time-of-flight–mass spectrometry (MALDI–TOF–MS), IR, ¹⁹F-,¹H-, and ¹³C-NMR, and GPC techniques. Molecular chain length and steric hindrance of monomers affected the product compositions. The NMR results show that there are different chemical shifts in the different ring-size macrocyclic poly arylene ether ketones in spite of having the same repeating unit. The crystallizability and thermal properties of small-size arylene ether ketone macrocycles were also investigated by DSC, WAXD, TGA, and the results suggest that the crystallization and thermal properties are related to their intrinsic chemical structures. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1957–1967, 1999     

Synthesis of amorphous block copoly(arylene ether ketones) and their characterization

Exchange reactions that may proceed in the course of polycondensation during formation of a polymer from 4,4′-difluorobenzophenone and 4,4′-(isopropylidene)diphenol have been studied. It has been shown that the molecular mass of the polymer decreases under the action of 4,4′-(isopropylidene)diphenol diphenolate. The nucleophilic substitution of the activated aryl halide in DMAA in the presence of potassium carbonate yields high-molecular-mass block copoly(arylene ether ketones) based on 4,4′-difluorobenzophenone and a number of bisphenols. It was demonstrated the synthetic procedure and the chemical structure of block copoly(arylene ether ketones) strongly affect the onset temperature of softening and the mechanical characteristics of the films based on these polymers.     

Homo- and copoly(arylene ether ketones) with side hydroxyl groups

The polycondensation of 2-β-oxyethyl-3,3-bis(4-oxyphenyl)phthalimidine with 4,4′-difluorobenzophenone proceeding via the nucleophilic substitution of the activated halogen atom in aryl halide has been studied. Conditions ensuring formation of noncrosslinked high-molecular-mass homo- and copoly(arylene ether ketones) containing side alcoholic hydroxyl groups (4,4′-difluorobenzophenone: a mixture of bisphenols: K₂CO₃: Na₂CO₃ = 1: 1: 1: 0.05) have been established. The polymers have M _w = (20–88.7) × 10³ and show good solubility in organic solvents; their onset temperatures of softening are in the range 195–250°C. Polymer films cast from solution are characterized by a breaking strength of 78–109 MPa.     

Synthesis and thermal properties of poly(arylene ether ketone)s containing phthalazinone moieties

A series of novel poly(arylene ether ketone)s were synthesized from the reaction of hydroquinone and 4-(4-hydroxyphenyl)-2,3-phthalazin-1-one with 4,4′-difluorobenzophenone in N-cyclohexylpyrrolidinone containing anhydrous potassium carbonate. The polymers exhibited high glass transition temperatures together with excellent thermooxidative stability. The chain structure of these polymers was studied by means of differential scanning calorimetry (DSC), wide-angle X-ray diffraction techniques (WAXD), and matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). The experimental results indicated that these “as-made” copoly(aryleneketone)s containing hydroquinone moieties exhibited a block chain structure with segments which mainly consisted of hydroquinone and 4,4′-difluorobenzophenone. These chain segments resulted in crystallites in the polymers although they are thermodynamically unstable. The polymers showed thermal properties comparable to commercial PEEK, but the conditions for synthesis are much milder. The glass transition temperatures and solubilities of the copoly(arylene ketone)s tended to increase with increasing phthalazinone moiety content, while the crystallite melting points and crystallinity appeared to decrease. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1781–1788, 1999     

Structure and properties of nanocomposites based on poly(arylene ether ketones) and metalalkoxysiloxanes

Nanocomposites obtained by in situ filling from amorphous poly(arylene ether ketones) based on 4,4´-difluorobenzophenone and 3,3-bis(4´-hydroxyphenyl)phthalide (phenolphthalein) with hydroxyl or benzophenone end groups were investigated. Metalalkoxysiloxanes, namely tris-(diethoxymethylsiloxy)iron, tetrakis-(diethoxymethylsiloxy)zirconium, and tetrakis- (diethoxymethylsiloxy)hafnium were used as precursors of the inorganic phase. It is shown that the morphology of the inorganic phase of nanocomposites can be varied from dispersed particles to a continuous network only by changing the type of the central metal atom of the metalalkoxysiloxane with the same organosilicon “framing”. The concentration of the precursor influences mainly the size of the filler particles. An application of tris-(diethoxymethylsiloxy)iron at a concentration of less than 14 wt.% makes it possible to obtain in situ filled polymers with a higher glass transition temperature than the ones obtained using tetrakis-(diethoxymethylsiloxy)zirconium or tetrakis-(diethoxymethylsiloxy)hafnium.     

General features of the reaction of 4,4′-difluorobenzophenone with potassium diphenoxide of 2,2-bis (4-hydroxyphenyl)propane

The major factors determining molecular weights of polyarylene-ether ketones formed by the reaction of 4,4-difluorobenzophenone with 2,2-bis(4-hydroxyphenyl)propane in the presence of K₂CO₃ were revealed. The optimum conditions for the preparation of high-molecular-weight polymers were found, and it was demonstrated that it is possible to control their molecular weights ( from 10 000 to 200 000).Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 10, pp. 2526–2530, October, 1996.     

Synthesis and characterization of 3-phenylethynyl endcapped matrix resins

The synthesis of 3-phenylethynylphenol, and its applicability as a high temperature cross-linking endcap for high T_g polyarylene ethers is described. It was synthesized in high yields and purity using the palladium catalyzed coupling reaction between the protected 3-bromo or iodo phenol and phenylacetylene. The yield of the reaction was found to be highly dependent on the structure of the halide used, the reaction temperature, and the concentration of phenylacetylene. The use of the protected phenol in the palladium catalyzed reaction was also extended to the high yield synthesis of 3-ethynylphenol and protected 4-ethynylphenols. The complete synthesis of 3-phenylethynylphenol, 3-ethynylphenol, and protected 4-ethynylphenol in high yields has been demonstrated and is discussed herein. Three new phenylethynyl functionalized arylene ether matrix resins have been synthesized in high yields and purity by reacting 3-phenylethynylphenol with 4,4′-dichlorodiphenyl sulfone, 4,4′-difluorobenzophenone, and bis(4-fluorophenyl)phenyl phosphine oxide, via nucleophilic poly(arylene ether) synthesis conditions. These low molecular weight materials undergo thermally induced chain extension/branching to yield an insoluble three-dimensional network at reaction temperatures of around 380°C. The low molecular weight arylene ethers endcapped with the phenylethynyl group demonstrate excellent flow characteristics and a wide processing window of about 250°C. Crosslinking of the 4,4′-bis(3-phenylethynyl phenoxy)diphenyl sulfone system for 30 min at 350°C in air afforded a T_g value of 265°C by differential scanning calorimetry measurements. Trace metal analysis for palladium and copper showed absence of these metals that would otherwise detract from the excellent thermal stability. The synthesis and characterization of these phenylethynyl endcapped arylene ether matrix resins is discussed. © 1995 John Wiley & Sons, Inc.     

Proton conductivity of poly(arylene ether ketones) with different sulfonation degrees: Improvement via incorporation of nanodisperse zirconium acid phosphate

The proton conductivity of films based on sulfonated poly(arylene ether ketone) derived from bisphenol A and 4,4′-difluorobenzophenone of various modification degrees has been studied. The conductivity achieves high levels upon incorporation of a large amount of sulfo groups into the polymer. The conductivity of the samples with low sulfonation degrees may be increased via introduction of the nanodisperse zirconium acid sulfate additive.     

Synthesis and properties of poly(arylene ether phenyl-s-triazine)s

A series of new poly(arylene ether phenyl-s-triazine)s was prepared by the nucleophilic aromatic substitution polymerization of the potassium salt of bisphenols with 2,4-bis (halophenyl)-6-phenyl-s-triazine in N-methyl-2-pyrrolidone at elevated temperature. The polymers with inherent viscosities exceeding 0.5 were obtained after polymerization for 1 h using 2,4-bis(fluorophenyl)-6-phenyl-s-triazine as a monomer. The glass transition temperatures of the resulting polymers ranged from 200 to 260°C depending on the bisphenol used in the polymer synthesis. The poly(arylene ether phenyl-s-triazine)s demonstrated excellent thermal stabilities in excess of 490°C (5% weight loss in air). The isothermal TGA measurements (400°C under air or nitrogen atmosphere) revealed that the 4,4'-biphenol- and hydroquinone-based poly(arylene ether phenyl-s-triazine)s belong to the most superior class of heat resistant polymers, such as polyimide Kapton?. The mechanical properties of these polymers are also described. © 1994 John Wiley & Sons, Inc.     

Synthesis and properties of poly(arylene ether sulfone)s and poly(arylene ether ketones) derived from 4,4″-dihydroxy-o-terphenyl

Novel poly(arylene ether)s with a rigid and zigzag 4,4″-o-terphenyldiyl structure, introduced into the polymer backbone were synthesized by nucleophilic displacement reaction of 4,4″-dihydroxy-o-terphenyl with several activated aromatic dihalides in virtually quantitative yields. The poly(arylene ether)s having high molecular weight show both good solubility in common organic solvents and high thermal stability up to 545°C. They are amorphous with glass transition temperatures of 160–200°C.     

Isolation,spectra, structure,and ring-opening polymerization of strained macrocyclic aryl(ether ketone) dimer

Macrocyclic arylene ether ketone dimer was isolated from a mixture of cyclic oligomers obtained by the nucleophilic substitution reaction of bisphenol A and 4,4′-difluorobenzophenone and easily polymerized to high molecular weight linear poly-(ether ketone). The cyclic compound was characterized by FTIR, ¹H- and ¹³C-NMR, and single-crystal x-ray diffraction. Analysis of the spectral and crystal structure reveals extreme distortions of the phenyl rings attached to the isopropylidene center and of the turning points of the molecular polygons. The release of the ring strain on ring-opening combined with entropical difference between the linear polymer chain and the more rigid macrocycle at temperatures of polymerization may be the proposed motivating factors in the polymerization of this precursor to high molecular weight poly(ether ketone). © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 1753–1761, 1997     

Comb-shaped homo- and copoly(arylene ether ketones) containing hydrophilic groups in side chains

Comb-shaped poly(arylene ether ketones) containing hydrophilic fragments in side chains are synthesized through the interaction of side reactive carboxyl groups of poly(arylene ether ketones) with methyl ethers of poly(ethylene glycol). Films based on these polymers possess tensile strengths up to 89 MPa and relative elongations at break up to 340%. Comb-shaped poly(arylene ether ketones) swell in water, and some of them show solubility in ethanol and methanol.     

Synthesis and characterization of poly(arylene ether)s derived from 4,4′‐bishydroxybiphenyl and 4,4′‐bishydroxyterphenyl

A series of poly(arylene ether)s were successfully prepared by aromatic, nucleophilic substitution reactions with various perfluoroalkyl‐activated bisfluoromonomers with 4,4′‐bishydroxybiphenyl and 4,4′‐bishydroxyterphenyl. 4,4′‐Bishydroxyterphenyl was synthesized through the Grignard coupling reaction of magnesium salt of 4‐bromoanisole with dibromobenzene followed by demethylation with pyridine–hydrochloride. The products obtained by the displacement of fluorine atoms exhibited good inherent viscosity, up to 0.77 dL/g, and number‐average molecular weights up to 69,300. These poly(arylene ether)s showed very good thermal stability, up to 548 °C for 5% weight loss according to thermogravimetric analysis under synthetic air, and high glass‐transition temperatures, up to 259 °C according to differential scanning calorimetry, depending on the exact repeat unit structure. These polymers were soluble in a wide range of organic solvents, such as N‐methylpyrrolidone, dimethylformamide, tetrahydrofuran, toluene, and CHCl₃, and were insoluble in dimethyl sulfoxide and acetone. Thin films of these poly(arylene ether)s showed good transparency and exhibited tensile strengths up to 132 MPa, moduli up to 3.34 GPa, and elongations at break up to 84%, depending on their exact repeating unit structures. These values are comparable to those of high‐performance thermoplastic materials such as poly(ether ether ketone) (PEEK) and Ultem poly(ether imide) (PEI). These poly(arylene ether)s exhibited low dielectric constants. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 55–69, 2002     

Side-Chain Sulfonated Poly(arylene ether)s for Fuel Cell Applications

Summary: Poly(arylene ether sulfone)s of high molecular weight and narrow molecular weight distribution were obtained by melt polycondensation of 4,4′-difluorodiphenyl- sulfone and trimethylsilylethers of 4,4′-dihydroxydiphenylsulfone and phenylhydroquinone using CsF as catalyst. Although a block-like structure of the polymers could be expected from the course of reaction, only a single T_g ranging from 190 °C to 230 °C could be detected by DSC and which depended on the copolymer composition. Contrary to the sulfonation of similar poly(ether ether ketone)s the poly(arylene ether sulfone)s here reported were sulfonated both in the side chain and the main chain. Nonetheless the sulfonated poly(arylene ether sulfone)s showed high hydrolytic stability in water at 130 °C.     

聚醚砜醚酮的合成与性能

以4,4′-二羟基二苯砜和4,4′-二氟二苯酮为单体, 通过溶液缩聚合成了聚醚砜醚酮(PESEK), 其分子结构相当于聚醚砜(PES)与聚醚醚酮(PEEK)的交替共聚物. 在共聚物分子中, 存在砜基、醚基和酮基, 整个结构单元形成了大共轭体系, 聚合物属无定形聚合物, 玻璃化转变温度(Tg)为198 ℃, 介于PEEK和PES的Tg之间, 其热稳定性和加工性能优于PES, 而力学性能与PES接近.     

Preparation of dibenzofuran-type amorphous polyetherketone by novel etherification reaction

4-Fluorobenzophenone reacted with potassium carbonate in the presence of silica catalyst in diphenyl sulfone solvent to yield 4,4′-dibenzoyldiphenyl ether. This new etherification reaction was extended to three difluoro aromatic ketones. 4,4′-Bis(4-fluorobenzoyl)diphenyl ether ( I ) reacted with potassium carbonate to yield a crystalline poly(oxy-1,4-phenylene-carbonyl-1,4-phenylene) (PEK) and 4,4′-bis{4-[4-(4-fluorobenzoyl)phenoxy]benzoyl}benzene ( II ) gave a crystalline poly(oxy-1,4-phenylene-carbonyl-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene-oxy-1,4-phenylene-carbonyl-1,4-phenylene-carbonyl-1,4-phenylene)(PEKEKEKK). 2,8-Bis(4-fluorobenzoyl)dibenzofuran ( III ) or 2,8-bis(4-chlorobenzoyl)dibenzofuran ( IV ) reacted with potassium carbonate to yield a poly(oxy-1,4-phenylene-carbonyl-2,8-dibenzofuran-carbonyl-1,4-phenylene) (PEKBK). The PEKBK was a noval amorphous polymer with the glass transition temperature of 222°C and it showed excellent thermal stability [T. Tanabe and I. Fukawa, Jpn. Pat., Kokai 64–74223 (1989)]. Several amorphous dibenzofuran type polyetherketone copolymers were prepared by coplycondensation of III with 4,4′-difluorobenzophenone ( V ) or 1,4-bis(4-fluorobenzoyl)benzene ( VI ) [T. Tanabe and I. Fukawa, Jpn. Pat., Kokai 1153722 (1989)]. © 1992 John Wiley & Sons, Inc.     

Synthesis and properties of polyether ketones

Polyether ketones were prepared by the nucleophilic reaction of dihaloaromatic ketones with aromatic bisphenols (hydroquinone, resorcinol and 4,4-dihydroxybenzophenone) using various solvents in the presence of anhydrous K₂CO₃. Dihaloaromatic ketones (4,4-difluorobenzophenone/4,4-dichlorobenzophenone) were prepared from the reaction of fluorobenzene/chlorobenzene with carbon tetrachloride in the form of AlCl₃. The polymers were characterized by different physico-chemical techniques. Thermogravimetric studies showed that all the polymers were stable upto 500°C with a char yield above 50% at 900°C in N₂ atmosphere. Isothermal degradation at 400°C under air and N₂ atmosphere reveals about 5% weight loss and about 1% weight loss at 75 min respectively. The effect of solvents, reaction temperature and reaction time on molecular weights are discussed. The effect of the annealing time on crystallinity of the polymers is also discussed.     

Polyamides containing arylene sulfone ether linkages

Polyamides containing arylene sulfone ether linkages were synthesized from 4,4′-[sulfonylbis(p-phenyleneoxy)] dibenzoyl chloride (SPCI), 3,3′-[sulfonylbis(p-phenyleneoxy)] dibenzoyl chloride (SMCl), and arylene sulfone ether diamines (SED), by solution and interfacial polymerization techniques. In solution polymerization, the effect of various acid acceptors such as propylene oxide (PO), lithium chloride (LiCl)/lithium hydroxide (LiOH), and triethylamine (TEA) on molecular weight of the polyamides was studied. The effect of methyl substituted and unsubstituted aromatic sulfone ether diamines on molecular weight and thermal properties of polyamides was also studied. The polyamides prepared were characterized by solution viscosity, elemental analysis, thermal gravimetric analysis, differential scanning calorimetry, and x-ray diffraction. Physical and thermal properties of polyamides prepared from SPCl and SED were compared with the polyamides prepared from SMCl and SED.     

Effect of crystal-disrupting chlorohydroquinone on the first-order transitions of poly(aryl ether ketone)s containing biphenyl units

The novel poly(aryl ether ketone)s were synthesized by nucleophilic substitution reactions of 4,4′-difluorobenzophenone with 4,4′-biphenyldiol and chlorohydroquinone. As expected, the copolymers have lower melting transitions than the biphenyldiol-based homopoly(aryl ether ketone) because of the copolymerization effect of the crystal-disrupting monomer chlorohydroquinone. Copolymers containing 50 and 70% biphenyldiol show two first-order transitions which are associated with the crystal-to-liquid crystal transition and the liquid crystal-to-isotropic transition.