Synthesis and properties of poly(aryl ether ketone ketone)/poly(aryl ether ether ketone ketone) copolymers with pendant cyano groups

2,6‐Diphenoxybenzonitrile (DPOBN) was synthesized by reaction of phenol with 2,6‐difluorobenzonitrile in N‐methyl‐2‐pyrrolidone in the presence of KOH and K₂CO₃. Poly(aryl ether ketone ketone)/poly(aryl ether ether ketone ketone) copolymers with pendant cyano groups were prepared by the Friedel–Crafts electrophilic substitution reaction of terephthaloyl chloride with varying mole proportions of diphenyl ether and DPOBN using 1,2‐dichloroethane as solvent and N‐methyl‐2‐pyrrolidone as Lewis base in the presence of anhydrous AlCl₃. The resulting polymers were characterized by various analytical techniques, such as FT‐IR, differential scanning calorimeter, thermal gravimetric analysis, and wide‐angle X‐ray diffraction. The crystallinity and melting temperature of the polymers were found to decrease with increase in concentration of the DPOBN units in the polymer. Thermogravimetric studies showed that all the polymers were stable up to 514°C in N₂ atmosphere. The glass transition temperature was found to increase with increase in concentration of the DPOBN units in the polymer when the molar ratios of DPOBN to DPE ranged from 10/90 to 30/70. The copolymers containing 30–40 mol % of the DPOBN units exhibit excellent thermostability at (350 ± 10)°C and have good resistance to acidity, alkali, and organic solvents. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 3601–3606, 2007     

Rheological properties in blends of poly(aryl ether ether ketone) and liquid crystalline poly(aryl ether ketone)

Rheological properties of the blends of poly(aryl ether ether ketone) (PEEK) with liquid crystalline poly(aryl ether ketone) containing substituted 3‐trifluoromethylbenzene side group (F‐PAEK), prepared by solution precipitation, have been investigated by rheometer. Dynamic rheological behaviors of the blends under the oscillatory shear mode are strongly dependent on blend composition. For PEEK‐rich blends, the systems show flow curves similar to those of the pure PEEK, i.e., dynamic storage modulus G′ is larger than dynamic loss modulus G″, showing the feature of elastic fluid. For F‐PAEK‐rich systems, the rheological behavior of the blends has a resemblance to pure F‐PAEK, i.e., G″ is greater than G′, showing the characteristic of viscous fluid. When the PEEK content is in the range of 50–70%, the blends exhibit an unusual rheological behavior, which is the result of phase inversion between the two components. Moreover, as a whole, the complex viscosity values of the blends are between those of two pure polymers and decrease with increasing F‐PAEK content. However, at 50% weight fraction of PEEK, the viscosity‐composition curves exhibit a local maximum, which may be mainly attributed to the phase separation of two components at such a composition. The changes of G′ and G″ with composition show a trend similar to that of complex viscosity. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4040–4044, 2006     

Miscibility and crystallization behavior of poly(ether ether ketone ketone)/poly(ether imide) blends

The miscibility and crystallization behavior of poly(ether ether ketone ketone) (PEEKK)/poly(ether imide) (PEI) blends prepared by melt‐mixing were investigated by differential scanning calorimetry. The blends showed a single glass transition temperature, which increased with increasing PEI content, indicating that PEEKK and PEI are completely miscible in the amorphous phase over the studied composition range (weight ratio: 90/10–60/40). The cold crystallization of PEEKK blended with PEI was retarded by the presence of PEI, as is apparent from the increase of the cold crystallization temperature and decrease of the normalized crystallinity for the samples anealed at 300°C with increasing PEI content. Although the depression of the apparent melting temperature of PEEKK blended with PEI was observed, there was no evidence of depression in the equilibrium melting temperature. The analysis of the isothermal crystallization at 313–321°C from the melt of PEEKK/PEI (100/0, 90/10, and 80/20) blends suggested that the retardation of crystallization of PEEKK is caused by the increase of the crystal surface free energy in addition to the decrease of the mobility by blending PEI with a high glass transition temperature. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 769–775, 2001     

间位苯基取代聚芳醚砜醚酮酮的合成与性能研究

以4,4′-二苯氧基二苯砜(DPODPS)、对苯二甲酰氯(TPC)和间苯二甲酰氯(IPC)为单体,无水AlCl3/二氯乙烷(DCE)/N,N-甲基甲酰胺(DMF)为催化溶剂体系,通过低温溶液共缩聚反应,合成系列聚芳醚砜醚酮酮(PESEKKs),用IR、DSC、WAXD、TG等技术对聚合物进行了结构和性能的表征,研究结果表明,随着高分子主链中间位苯基结构单元的增加,对共聚玻璃化转变温度(Tg)和热分解温度(Td)影响不大,熔融温度(Tm)和结晶则逐渐降低,但仍保持良好的耐热性,溶解性等到很大改善。     

Isothermal and nonisothermal melt crystallization kinetics of a novel poly(aryl ether ketone ether ketone ketone) containing a meta‐phenyl linkage

The isothermal and nonisothermal melt crystallization kinetics of a novel poly(aryl ether ketone ether ketone ketone) containing a meta‐phenyl linkage (PEKEKmK) were studied by differential scanning calorimetry. The Avrami equation was used to analyze the isothermal crystallization kinetics of PEKEKmK. The crystallization mechanism did not change within the crystallization temperature range, but the crystallization rate decreased with an increase in the crystallization temperature. The equilibrium melting point, T, was determined to be 327°C according to the Hoffman–Weeks equation. Moreover, the nonisothermal crystallization kinetics of PEKEKmK was also investigated by the Avrami equation as modified by Jeziorny. It was found that the nonisothermal crystallization behavior of PEKEKmK could be described well by this method at various cooling rates, although the parameters n and Z_c did not have the same clear physical meaning as for isothermal crystallization kinetics. The thermal properties and crystallization characteristics of PEKEKmK were compared with those of all‐para PEKEKK(T) and PEKEKK(T/I) with a T/I ratio of 1. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 4775–4779, 2006     

Rheological and crystallization behaviors of low processing temperature poly(aryl ether ketone)

A new low melting temperature poly(aryl ether ketone) (PAEK) thermoplastic polymer (Victrex AE 250) was investigated through thermal and rheological analysis of films and flakes. DSC was assigned to evaluate the influence of cooling rate on crystallinity and thermal transitions. Rheometry was used to assess its flowing behavior through the evaluation of dynamic moduli and complex viscosity in the melted state. The relaxation times were found from the rheological curves: they are between a few ms to 200 ms for AE 250, lower than those found for PEEK 450, meaning a faster mobility of macromolecules. The thermal activation energy, E_a obtained from Time Temperature Superposition is the same for films and flakes in spite of a lower viscosity for flakes. The molecular weight between entanglements is evaluated at 8000 g.mol⁻¹ for FMc and 13,000 for FLc, it is compared to the value of about 2000 g.mol⁻¹ found for PEEK 450 with the same procedure. Also, the viscosity was compared to other commercial PAEK such as PEEK and PEKK based on data from the literature. This polymer appears very efficient to compete with high performance thermoplastics to be processed by compression molding, out of autoclave consolidation, additive manufacturing, and welding.     

Crosslinkable fully aromatic poly(aryl ether ketone)s bearing macrocycle of aryl ether ketone

A novel bisphenol monomer, (3-methoxy)phenylhydroquinone, was synthesized via a three-step synthetic procedure. The cyclization of the bisphenol monomer and 4,4-difluorobenzophenone was carried out under pseudo high dilution condition. Two types of fully aromatic poly(aryl ether ketone)s were prepared by copolymerization of macrocycle of aryl ether ketone (MACEK) containing hydroxyphenyl, 4,4′-(hexafluoroisopropylidene)diphenol (HFBPA), and 4,4-difluorobenzophenone. The copolymers have high molecular mass, good solubility and high glass transition temperatures. The copolymers are crosslinkable in the presence of basic initiator and the glass transition temperatures of the copolymers increased greatly after the curing. These cured copolymers exhibit excellent thermal stability, and the 5% weight loss temperatures are around 500 °C in nitrogen.     

Synthesis and curing behavior of macrocycle‐terminated poly(aryl ether ketone)s

BACKGROUND: The introduction of poly(ether ether ketone)‐based carbon‐fiber composites accelerated the application of poly(ether ether ketone)s in advanced composite materials. In order to improve the compatibility and processability with reinforced components, polymers with low melt viscosity are preferable. RESULTS: Novel fully aromatic macrocycle‐terminated poly(aryl ether ketone)s (MCPAEKs) were prepared by condensation of macrocyclic aryl ether ketone dimers containing hydroxyphenyl groups and fluorine end‐capped poly(aryl ether ketone) oligomers. Compared with liner poly(aryl ether ketone)s, MCPAEKs showed much lower melt viscosities at low temperature. In the presence of caesium fluoride, the crosslinking reaction of MCPAEKs afforded fully aromatic thermoset poly(aryl ether ketone)s by ring‐opening reaction. CONCLUSION: The MCPAEKs exhibited high thermal stability due to their wholly aromatic structures. After crosslinking, the glass transition temperatures and complex melt viscosities of the polymers were increased greatly. Although there was some residual cesium fluoride or phenoxides produced by ring‐opening reaction, the thermoset poly(aryl ether ketone)s obtained had good thermal stability with temperatures at 5% weight loss above 475 °C. Copyright © 2009 Society of Chemical Industry     

Synthesis and properties of copolymers of poly(ether ketone ketone) and poly(ether amide ether amide ether ketone ketone)

Poly(aryl ether ketone)s (PAEKs) are a class of high‐performance engineering thermoplastics known for their excellent combination of chemical, physical and mechanical properties, and the synthesis of semicrystalline PAEKs with increased glass transition temperatures (T_g) is of much interest. In the work reported, a series of novel copolymers of poly(ether ketone ketone) (PEKK) and poly(ether amide ether amide ether ketone ketone) were synthesized by electrophilic solution polycondensation of terephthaloyl chloride with a mixture of diphenyl ether and N,N′‐bis(4‐phenoxybenzoyl)‐4,4′‐diaminodiphenyl ether (BPBDAE) under mild conditions. The copolymers obtained were characterized using various physicochemical techniques. The copolymers with 10–35 mol% BPBDAE are semicrystalline and have markedly increased T_g over commercially available poly(ether ether ketone) and PEKK due to the incorporation of amide linkages in the main chain. The copolymers with 30–35 mol% BPBDAE not only have high T_g of 178–186 °C, but also moderate melting temperatures of 335–339 °C, having good potential for melt processing. The copolymers with 30–35 mol% BPBDAE have tensile strengths of 102.4–103.8 MPa, Young's moduli of 2.33–2.45 GPa and elongations at break of 11.7–13.2%, and exhibit high thermal stability and good resistance to organic solvents. Copyright © 2010 Society of Chemical Industry     

Thermal crosslinking behavior of poly (aryl ether ketone) copolymers containing naphthalene moieties

A series of poly[(ether ether ketone)‐co‐(ether naphthalene ether ketone)] (P(EEK‐co‐ENEK)) copolymers were heated under a variety of conditions. The thermal crosslinking behavior was monitored by differential scanning calorimetry (DSC), electron spin resonance (ESR) and wide‐angle X‐ray diffraction (WAXD). The results indicate that under a non‐oxidative environment such as nitrogen P(EEK‐co‐ENEK) is more stable, while under oxidative conditions a crosslinking reaction takes place that causes a reduction in the crystallizability of the copolymers, and an increase in the concentration of free radicals on the copolymer. ESR results suggest that the crosslinking reaction proceeds via free radicals. Subsequently two kinds of free radicals were characterized: one is an RO^? type free radical and the other is a naphthalene ring free radical. Copyright © 2004 Society of Chemical Industry     

含氰侧基联苯型聚芳醚醚酮酮的合成及表征

通过一种反应条件较为温和的反应新工艺,合成联苯二甲酰氯,即4,4’-二氯甲酰基联苯(BC IBP)。然后,在无水A lC l3及N-甲基吡咯烷酮(NMP)/1,2-二氯乙烷(DCE)复合溶剂的存在下,将2,6-二苯氧基苯甲腈(DPOBN)与BC IBP进行低温缩聚反应,合成了一类新型含氰侧基联苯型聚芳醚醚酮酮。用IR,DSC,TG,WAXD及元素分析等方法对其结构和性能进行了表征。结果表明,所合成的聚合物具有预期结构且为非晶态聚合物;其玻璃化转变温度(Tg)为211℃,在氮气气氛中及在空气气氛中的热分解5%的温度(Td)分别为523℃及498℃,说明其具有突出的耐高温性能;聚合物除了能在浓H2SO4,CF3COOH/CHC l3等强质子性溶剂当中溶解外,对其他的溶剂均不溶解,说明聚合物具有优异的耐化学腐蚀性能。     

Synthesis and characterization of novel poly(aryl ether ketone ketone)s containing the o‐dibenzobene moiety

The synthesis of a novel chloro monomer containing the 1,2‐dibenzoylbenzene moiety was described. The chloro monomer was reacted with 4‐(4‐hydroxyphenyl)‐1(2H)‐phthalazinone compound in the presence of excess anhydrous potassium carbonate in an aprotic solvent (Sulfolane), and high molecular weight amorphous poly(aryl ether ketone ketone) was synthesized. The polymers with high glass transition temperature were soluble in solvents such as chloroform and nitrobenzene at room temperature and easily cast into flexible, colorless, and transparent films. The 5% weight loss of the polymers was >400 °C. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1487–1492, 2001     

Investigation on the crystallization behavior of poly(ether ether ketone)/poly(phenylene sulfide) blends

The morphology of nonisothermally crystallized poly(phenylene sulfide) (PPS) and its blend with poly (ether ether ketone) (PEEK) have been observed by polarized optical microscope (POM) equipped with a hot stage. The nonisothermal crystallization behavior of PPS and PEEK/PPS blend has also been investigated by differential scanning calorimetry (DSC). The maximum crystallization temperature for PEEK/PPS blend is about 15°C higher than that of neat PPS, and the crystallization rate, characterized by half crystallization time, of the PEEK/PPS blend is also higher than that of the neat PPS. These results indicate that the PEEK acts as an effective nucleation agent and greatly accelerates the crystallization rate of PPS. The Ozawa model was used to analyze the nonisothermal crystallization kinetics of PPS and its blends. The Avrami exponent values of neat PPS are higher than that of its blend, which shows that the presence of PEEK changed the nucleation type of PPS from homogeneous nucleation to heterogeneous nucleation. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Preliminary investigation of poly(ether sulfone)/poly(aryl ether ketone) containing 1,4‐naphthalene blends

The blends of poly(ether sulfone) and poly(aryl ether ketone) containing 1,4‐naphthalene were prepared by melt mixing in a Brabender‐like apparatus. The specimens for measurements were made by compression molding under pressure and then were water‐quenched at room temperature. The tensile strength, tensile modulus, elongation at break, thermal analysis, and scanning electron microscopy were each measured. The dependence of tensile strength, tensile modulus, and elongation at break on blend systems was obtained. The effects of composition and miscibility on the mechanical properties are discussed. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 99: 472–476, 2006     

聚芳醚砜酮纤维的热性能

采用DSC、TG测定了含联苯结构聚芳醚砜酮 (PPESK)纤维的热性能 ,结果表明 ,纤维的玻璃化温度随砜酮比的增大而提高 ,纤维的起始分解温度大于 463℃。当砜酮比为 15 / 85 ,5 0 / 5 0 ,75 / 2 5时 ,纤维的玻璃化温度分别为 2 5 7.62 ,2 78.64 ,2 79.71℃ ;热分解活化能分别为 15 0 .8,2 19.9,195 .5kJ/mol;热分解反应级数分别为 1,1.76,1级     

Synthesis and characterization of poly(ether ketone ether ketone ketone)/poly(ether ether ketone ketone) copolymers containing naphthalene and pendant cyano groups

2,6‐Bis(β‐naphthoxy)benzonitrile (BNOBN) was synthesized by reaction of β‐naphthol with 2,6‐difluorobenzonitrile in N‐methyl‐2‐pyrrolidone (NMP) in the presence of KOH and K₂CO₃. Poly(ether ketone ether ketone ketone)(PEKEKK) /poly(ether ether ketone ketone) (PEEKK) copolymers containing naphthalene and pendant cyano groups were obtained by electrophilic Friedel‐Crafts polycondensation of terephthaloyl chloride (TPC) with varying mole proportions of 4,4′‐diphenoxybenzophenone (DPOBP) and 2,6‐bis(β‐naphthoxy)benzonitrile (BNOBN) using 1,2‐dichloroethane (DCE) as solvent and NMP as Lewis base in the presence of anhydrous AlCl₃. The resulting polymers were characterized by various analytical techniques, such as FTIR, DSC, TG, and WAXD. The results indicated that the crystallinity and melting temperature of the polymers decreased with increase in concentration of the BNOBN units in the polymer, the glass transition temperature of the polymers increased with increase in concentration of the BNOBN units in the polymer. Thermogravimetric studies showed that all the polymers were stable up to 536°C in N₂ atmosphere. The copolymers have good resistance to acidity, alkali, and organic solvents. Because of the melting temperature (T_m) depression with increase in the BNOBN content in the reaction system, the processability of the resultant coplymers could be effectively improved. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

Fine poly(ether ether ketone) powders

The physical form of polymers is often important for carrying out subsequent processing operations. For example, fine powders are desirable for molding and sintering compounds because they consolidate to produce void free components. The objective of this work is to prepare fine polymeric particulates suitable for processing into fiber reinforced polymer matrix composites. Micron size particles of poly(ether ether ketone) (PEEK) were prepared by rapidly quenching solutions of these materials. PEEK pellets were dissolved at temperatures near the PEEK melting point in a mixture of terphenyls and quaterphenyls; then the solution was quenched to a temperature between the T_g and T_m (≈ 225°C) by adding a room temperature eutectic mixture of diphenyl ether and biphenyl. A supersaturated, metastable solution of PEEK resulted, causing rapid nucleation. Fine PEEK particles rapidly crystallized from this solution. The average particle size was measured using transmission electron microscopy, atomic force microscopy, and by light scattering of aqueous suspensions which had been fractionated by centrifugation. The average particle diameter was about 0.6 μm. Three dimensional photomicrographs obtained via atomic force microscopy showed some aggregates in the suspensions. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 63: 1571–1578, 1997     

Synthesis and characterization of poly(ether amide ether ketone)/poly(ether ketone ketone) copolymers

A new monomer, N,N′‐bis(4‐phenoxybenzoyl)‐m‐phenylenediamine (BPPD), was prepared by condensation of m‐phenylenediamine with 4‐phenoxybenzoyl chloride in N,N‐dimethylacetamide (DMAc). A series of novel poly(ether amide ether ketone) (PEAEK)/poly(ether ketone ketone) (PEKK) copolymers were synthesized by the electrophilic Friedel‐Crafts solution copolycondensation of terephthaloyl chloride (TPC) with a mixture of diphenyl ether (DPE) and BPPD, over a wide range of DPE/BPPD molar ratios, in the presence of anhydrous AlCl₃ and N‐methylpyrrolidone (NMP) in 1,2‐dichloroethane (DCE). The influence of reaction conditions on the preparation of copolymers was examined. The copolymers obtained were characterized by different physicochemical techniques. The copolymers with 10–25 mol % BPPD were semicrystalline and had remarkably increased T_gs over commercially available PEEK and PEKK due to the incorporation of amide linkages in the main chains. The copolymers III and IV with 20–25 mol % BPPD had not only high T_gs of 184–188°C, but also moderate T_ms of 323–344°C, having good potential for the melt processing. The copolymers III and IV had tensile strengths of 103.7–105.3 MPa, Young's moduli of 3.04–3.11 GPa, and elongations at break of 8–9% and exhibited outstanding thermal stability and good resistance to organic solvents. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis of a new electroactive poly(aryl ether ketone)

In this communication, we report for the first time the synthesis of a new electroactive poly(aryl ether ketone) derived from the phenyl-capped aniline tetramer. The general properties are studied by differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The polymer has high serving temperature and good thermal stability. And its chemical oxidation process was studied by UV-Vis spectra. It was found the polymer was oxidized to its EB form and then to the pernigraniline oxidation state, which is same as the PANI.     

环氧树脂/聚芳醚酮共混物的制备研究

用热塑性酚酞型聚芳醚酮树脂(PEK-C)与环氧树脂(EP)熔融共混,并以4,4′-二氨基二苯甲烷(DDM)为固化剂制备新型改性环氧树脂。用SEM观察固化物的微观相结构,用DMA、TG-DTG测试固化物的热性能及2相的相容性。结果表明,PEK-C质量分数小于10%时可以分子或纳米尺度(<100nm)均匀分散于环氧树脂基体中;PEK-C的含量增大,相分离现象明显,固化物的Tg升高,但在300℃以上的高温热稳定性能下降。