Glass transition and miscibility in blends of two semicrystalline polymers: Poly(aryl ether ketone) and poly(ether ether ketone)

Binary melt‐blended mixtures of two aryl ether ketone polymers (i.e., a new poly(aryl ether ketone) (code name PK99) and poly(ether ether ketone) (PEEK), have been studied. Polymer miscibility in glassy amorphous (or melt) domains has been demonstrated for the binary blend comprising of two aryl‐ether‐ketone‐type semicrystalline polymers. Composition‐dependent, single T_g was observed within full composition range in the PK99/PEEK blends, and the narrow T_g breadth also suggests that the scale of mixing was fine and uniform. To better resolve any possible overlapping T_g's, physical aging was imposed on a comparison set of blend samples for the purpose of improving detectability of overlapped multiple transitions if existing. The result still showed one single T_g. The relative sharp T_g and lack of cloud point transition suggest that the scale of molecular intermixing is good. Phase homogeneity was further confirmed using optical and scanning electron microscopy. The X‐ray diffractograms suggest that isomorphism does not exist in the PK99/PEEK blends and that the crystal forms of the respective polymers remain distinct and unchanged by the miscibility in the amorphous region. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 1485–1494, 1999     

聚醚醚酮酮结晶度研究

聚醚醚酮酮结晶度研究刘天西，王尚尔，张宏放，莫志深（中国科学院长春应用化学研究所高分子物理联合开放研究实验室长春１３００２２）那辉，王军佐，吴忠文（吉林大学化学系长春）关键词聚醚醚酮酮，广角Ｘ射线衍射，结晶度新型特种工程塑料聚醚醚酮酮（ＰＥＥＫＫ）具...     

Poly(ether ether ketone)/poly(aryl ether sulfone) blends: Melt rheological behavior

Dynamic rheological measurements were carried out on blends of poly(ether ether ketone) (PEEK)/poly(aryl ether sulfone) (PES) in the melt state in the oscillatory shear mode. The data were analyzed for the fundamental rheological behavior to yield insight into the microstructure of PEEK/PES blends. A variation of complex viscosity with composition exhibited positive–negative deviations from the log‐additivity rule and was typical for a continuous‐discrete type of morphology with weak interaction among droplets. The point of transition showed that phase inversion takes place at composition with a 0.6 weight fraction of PEEK, which agreed with the actual morphology of these blends observed by scanning electron microscopy. Activation energy for flow, for blend compositions followed additive behavior, which indicated that PEEK/PES blends may have had some compatibility in the melt. Variation of the elastic modulus (G′) with composition showed a trend similar to that observed for complex viscosity. A three‐zone model used for understanding the dynamic moduli behavior of polymers demonstrated that PEEK follows plateau‐zone behavior, whereas PES exhibits only terminal‐zone behavior in the frequency range studied. The blends of these two polymers showed an intermediate behavior, and the crossover frequency shifted to the low‐frequency region as the PEEK content in PES increased. This revealed the shift of terminal‐zone behavior to low frequency with an increased PEEK percentage in the blend. Variation of relaxation time with composition suggested that slow relaxation of PEEK retards the relaxation process of PES as the PEEK concentration in the blend is increased because of the partial miscibility of the blend, which affects the constraint release process of pure components in the blend. A temperature‐independent correlation observed in the log–log plots of G′ versus loss modulus (G″) for different blend systems fulfilled the necessary condition for their rheological simplicity. Further, the composition‐dependent correlations of PEEK/PES blends observed in a log–log plot of G′ versus G″ showed that the blends are either partially miscible or immiscible and form a discrete‐continuous phase morphology. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 1548–1563, 2004     

气相色谱法探究聚醚醚酮的热降解及热氧化降解（英文）

Poly(ether ether ketone)(PEEK)was synthesized via polycondensation of hydroquinone with 4,4′-difluorobenzophenone at 320℃for 5 h.Thermal and thermo-oxidative degradation of PEEK was studied over a wide range of temperatures.In an inert medium,decomposition of the polymer occurred in one stage,with the formation of a coke residue accounting for approximately 50%of the original polymer mass.In air,the mass loss curve exhibited two distinct stages.The first stage involved breakdown of the main polymer chain,the speed of which indicated a radical chain failure mechanism.In the second stage,the rate of mass loss clearly decreased,indicating a transition from the radical chain failure mechanism to simple combustion reactions(wherein the polymer combusted completely).To further investigate the nature of the processes occurring during the pyrolysis of PEEK,the investigations were carried out using gas chromatograph under isothermal conditions.It was concluded that during thermal degradation,the decomposition of the polymer starts with the rupture of ketone and ether bonds and proceeds to destruction of the benzene ring at higher temperatures,which is accompanied by the formation of H2O and CH4.Above 500℃,the polymer degradation further involved thermohydrolysis.The thermo-oxidation of PEEK,which was accompanied mainly by the formation ofH2,was noticeable beginning at 325℃.The total yield of the latter indicated oxidation of fragments of the benzene ring.     

聚醚醚酮醚酮的合成与表征

聚醚醚酮（ＰＥＥＫ）自工业化以来［１］，由于其优异的性能已在机械、航天等领域得到广泛应用．各种聚芳醚酮类聚合物相继被开发出来．但以亲电缩聚路线制备聚醚醚酮醚酮（ＰＥＥＫＥＫ）的报道较少［２］．本文以二苯醚和４－氟苯甲酰氯为主要反应试剂，采取付氏酰基化...     

3种新型聚苯基醚喹噁啉的合成

用4,4′-二氟代二苯甲酰与双酚A的溶液缩聚制得聚醚苯偶酰(PEB),经邻苯二胺改性后,通过两步法得到聚苯基醚喹噁啉（PEQ-1）。 在PEB的改性反应中加入质量分数分别为1.0%和1.3%的3,3′,4,4′-四胺基二苯醚,可有效增加聚苯基醚喹噁啉的相对分子质量,得到PEQ-2和PEQ-3（总收率≥90%）,其质均相对分子质量分别为7.492×104和1.486×105。 并用IR、 NMR等对这些聚合物进行了表征。 该法操作简便,具有潜在的应用价值。     

Thermal conductivity of poly(ether ether ketone) and its short-fiber composites

The effects of crystallinity, orientation, and short-fiber filler on the thermal diffusivity D and thermal conductivity K of poly (ether ether ketone) (PEEK) have been studied. Below the glass transition, D increases by less than 10% as the crystallinity increases from 0 to 0.3. For amorphous PEEK, there is an abrupt drop in D at the glass transition (T_g ? 420 K). The drop is less prominent for the 30% crystalline sample and occurs at 20 K higher. At a draw ratio of 2.5, the axial thermal conductivity is 2.3 times higher while the transverse thermal conductivity is 30% lower than that of the unoriented material. For an injection-molded bar of carbon fiber reinforced PEEK, the variation of D with position along the width or thickness direction is found to correlate well with the fiber orientation. By regarding the injection-molded bar as a multidirectional laminate comprising a large number of unidirectional plies, the thermal conductivities along the longitudinal and transverse direction are calculated and found to agree closely with the experimental data. © 1994 John Wiley & Sons, Inc.     

Sequence analysis of poly (ether sulfone) copolymers by 13C NMR

Random and block copolymers of poly (ether sulfone) (PES) and poly (ether ether sulfone) (PEES) were synthesized by the nucleophilic polycondensation of 4,4′‐dichlorodiphenyl sulfone (DCDPS) with 4,4′‐dihydroxydiphenyl sulfone (DHDPS) and hydroquinone (HQ). Chemical structures of these copolymers were characterized by ¹³C NMR. The monomer molar fraction, sequential distribution, and degree of randomness of the copolymers were determined through analyses of the resonances of quaternary carbons in the DCDPS unit. Experimental results show that the molar fractions of the comonomer determined by ¹³C NMR analyses are close to the charged values in the synthetic step. Moreover, these copolymers, which were prepared by different polymerization methods, revealed different number‐average sequential length and degree of randomness. © 2005 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 43: 1624–1630, 2005     

Synthesis and characterization of poly(ether naphthalimide)s

A series of new poly(ether imide)s containing the naphthalimide moiety were prepared from bis(4-fluorobenzoyl)naphthalimides and several bisphenols by aromatic nucleophilic displacement polymerization. These polyimides had inherent viscosities in the range of 0.31–1.04 dL/g in chloroform and glass transition temperatures of 283.0–341.6°C by differential scanning calorimetry. The onset temperature for 5% weight loss for all the polymers was over 448°C, as assessed by thermogravimetry at a heating rate 10°C/min in nitrogen. In addition, these novel polyimides exhibited good solubility in organic solvents including N-methyl-2-pyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, 1,1,2,2-tetrachloroethane and chloroform. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3227–3231, 1999     

新型含磷双酚A型共聚醚醚酮的合成与性能

新型含磷双酚A型共聚醚醚酮的合成与性能;溶液缩聚;含磷单体     

Microcellular processing and relaxation of poly(ether ether ketone)

The semicrystalline microcellular closed‐cell foams are prepared by a two‐stage batch foaming process from poly(ether ether ketone) and characterized by scanning electronic microscopy. It can be observed that there are two kinds of cells with obviously different cellular sizes in the same transect and the distribution of larger cells (about 7 μm) looks like sandwich. The effects of foaming temperatures and transfer times on the cellular sizes and cell densities of porous materials were discussed. Particular emphasis was given to the effects of crystalline on the microcellular morphology. The relaxation mechanism of microcellular materials was systemically investigated by dynamic mechanics analysis. A plain on the storage modulus curve before T_g was observed due to the densification of cells. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 2890–2898, 2007     

Relationship between morphology and glass transition temperature in solvent-crystallized poly(aryl ether ketones)

The relationship between semicrystalline morphology and glass transition temperature has been investigated for solvent-crystallized poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK). Solvent-crystallized specimens of both PEEK and PEKK displayed a sizeable positive offset in T_g compared to quenched amorphous specimens as well as thermally crystallized specimens of comparable bulk crystallinity; the offset in T_g for the crystallized samples reflected the degree of constraint imposed on the amorphous segments by the crystallites. Small-angle X-ray scattering studies revealed markedly smaller crystal long periods (d) for the solvent-crystallized specimens compared to samples prepared by direct cold crystallization. The strong inverse correlation observed between T_g and interlamellar amorphous thickness (l_A) based on a simple two-phase model was in excellent agreement with data reported previously for PEEK, and indicated the existence of a unique relationship between glass transition temperature and morphology in these poly(aryl ether ketones) over a wider range of sample preparation history and lamellar structure than was previously reported. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36 : 65–73, 1998     

Synthesis and characterization of aromatic poly(ether sulfone imide)s derived from sulfonyl bis(ether anhydride)s and aromatic diamines

Two sulfonyl group-containing bis(ether anhydride)s, 4,4′-[sulfonylbis(1,4-phenylene)dioxy]diphthalic anhydride ( IV ) and 4,4′-[sulfonylbis(2,6-dimethyl-1,4-phenylene)dioxy]diphthalic anhydride (Me- IV ), were prepared in three steps starting from the nucleophilic nitrodisplacement reaction of the bisphenolate ions of 4,4′-sulfonyldiphenol and 4,4′-sulfonylbis(2,6-dimethylphenol) with 4-nitrophthalonitrile in N,N-dimethylformamide (DMF). High-molar-mass aromatic poly(ether sulfone imide)s were synthesized via a conventional two-stage procedure from the bis(ether anhydride)s and various aromatic diamines. The inherent viscosities of the intermediate poly(ether sulfone amic acid)s were in the ranges of 0.30–0.47 dL/g for those from IV and 0.64–1.34 dL/g for those from Me- IV. After thermal imidization, the resulting two series of poly(ether sulfone imide)s had inherent viscosities of 0.25–0.49 and 0.39–1.19 dL/g, respectively. Most of the polyimides showed distinct glass transitions on their differential scanning calorimetry (DSC) curves, and their glass transition temperatures (T_g) were recorded between 223–253 and 252–288°C, respectively. The results of thermogravimetry (TG) revealed that all the poly(ether sulfone imide)s showed no significant weight loss before 400°C. The methyl-substituted polymers showed higher T_g's but lower initial decomposition temperatures and less solubility compared to the corresponding unsubstituted polymers. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 1649–1656, 1998     

含间位聚醚酮醚酮酮的合成与结晶

聚芳醚酮类聚合物因其综合性能优异而在高技术领域得到广泛应用．这些高聚物的主链大都为全对位连接,使其熔点较高以至加工难度增大．如果在聚合物主链中引入间位结构,则可在对玻璃化转变温度影响较小的情况下降低熔点来改善加工条件［１］．含间位聚醚酮醚酮酮（ＰＥＫＥＫｍＫ）也是其中一种．本文主要研究ＰＥＫＥＫｍＫ的合成、基本物性与结晶行为．样品的合成与制备：单体４,４′双（对苯氧基）二苯甲酮按文献［２］方法合成．聚合物参照文献［３］合成．将粉末样品在油压机上熔融后快速取出投入冰水中淬火得无定形样品,或将熔融…     

Controlled sulfonation of poly(arylene ether sulfone)s and poly(arylene ether ketone)s with different molecular structures for polymer electrolyte membranes

Poly(arylene ether sulfone) copolymers derived from 9,9-bis(4-hydroxyphenyl)fluorene, bisphenol S and 4,4′-difluorodiphenylsulfone and poly(arylene ether ketone) copolymers derived from 4-phenoxybiphenyl, diphenyl ether and isophthaloyl chloride were prepared as precursor polymers for sulfonation reaction in which sulfonic groups are introduced quantitatively into specified positions. Sulfonation reaction for these two series of copolymers by concentrated sulfuric acid was successfully carried out to give sulfonated polymers with controlled positions and degree of sulfonation. Thermal stability, moisture absorption and proton conductivity for these two series of copolymers were measured and the results were compared to those of perfluorosulfonic acid polymers.     

Synthesis and characterization of soluble copoly(ether ketone)s containing double bonds

A series of copoly(ether ketone)s containing double bonds along the polymer chains were synthesized from the condensation polymerization of hydroquinone with 4,4′‐difluorobenzophenone and 4,5‐bis(4‐fluorobenzoyl)‐1‐methylcyclohexene in sulfolane containing anhydrous potassium carbonate. The presence of methylcyclohexene in the polymer chains resulted in an improvement in the solubility of poly(ether ketone)s in organic solvents such as chloroform, chlorobenzene, and sulfolane. As a result, the conditions for synthesizing these polymers were much milder than those for poly(ether ether ketone). The new copoly(ether ketone)s also showed good tensile properties and reasonable thermal stability. New polyethers containing pyrazine unites were obtained from the cyclization reaction of these copoly(ether ketone)s with hydrazine. The hydrazine cycloderivatives led to an increase in the glass‐transition temperatures and a decrease in solubility in organic solvents. © 2002 Government of Canada. Exclusive world‐wide publication rights in the article have been transferred to Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 3449–3454, 2002     

Sulphonated poly(ether ether ketone): synthesis and characterisation

The paper describes the sulphonation of commercially available poly(ether ether ketone) PEEK (GATONE^TM, Gharda Chemicals Limited, India and VICTREX^®, ICI Limited, UK) by using concentrated sulphuric acid. The concentration of GATONE in conc. H₂SO₄ was varied from 4-10% (w/v) whereas in VICTREX^® the concentration was 4% (w/v). The temperature was varied from 35-55°C and the duration of reaction was 3-7 h. Structural characterisation of sulphonated polymers was done by elemental analysis, FT-IR and ¹H-NMR spectroscopy. On the basis of elemental analysis, the extent of sulphonation of GATONE was found to be 57-75%. The extent of sulphonation as determined by ¹H-NMR in case of GATONE was in the range of 53-80% and for VICTREX 58-87%. Thermal analysis, proton conductivity and water uptake of these samples were also studied. Proton conductivity of the films was comparable to the perflourinated polymer (Nafion).     

The double-melting behavior of poly(ether diphenyl ether ketone)

Poly(ether diphenyl ether ketone) (PEDEK) synthesized by the nucleophilic route has the following chemical structure: At some given temperatures for a given time isothermally crystallized PEDEK sample exhibits two endothermic peaks which are similar to PEEK and PEEKK. The melting behavior of PEDEK crystallized from the glassy state is investigated through differential scanning calorimeter (DSC). We consider that the high-melting peak is related to the perfect crystals and the low-melting peak is associated with a few imperfect crystals. © 1997 John Wiley & Sons, Inc.     

Synthesis and Characterization of a Novel Poly(aryl ether) Containing 4-Chloro-2,5-diphenyloxazole

4-Chloro-2,5-bis(4-fluorophenyl)oxazole monomer has successfully been synthesized using cyclization reaction of 4-fluorobenzoyl cyanide with 4-fluorobenzaldehyde. This monomer was converted to poly(aryl ether)s by nucleophilic substitution of the fluorine atoms on the benzene rings of oxazole monomer with bisphenol A. The influence of the reaction time on the molecular weight had been investigated. The polymers were identified by FT-IR,¹H-NMR and TGA. The products exhibited weight-average molar masses up to 2.81 x 10⁴g mol⁻¹ in GPC. These poly(aryl ether)s showed very high thermal stability up to 363 °C for 5 % weight loss in TGA under N₂.