Synthesis and properties of novel poly(aryl ether ketone)s containing both diphenyl moiety and amide linkages in the main chains

New monomers, 4,4′-bis(4-phenoxybenzoyl)diphenyl (BPOBDP) and N,N′-bis(4-phenoxybenzoyl)-p-phenylenediamine (BPBPPD), were conveniently synthesized via simple synthetic procedures from readily available materials. A series of novel poly(aryl ether ketone)s containing both diphenyl moiety and amide linkages in the main chains were prepared by electrophilic Friedel-Crafts solution copolycondensation of isophthaloyl chloride (IPC) with a mixture of BPOBDP and BPBPPD, over a wide range of BPOBDP/BPBPPD molar ratios, in the presence of anhydrous AlCl₃ and N-methylpyrrolidone (NMP) in 1,2-dichloroethane (DCE). All the polymers are semicrystalline and had remarkably increased T_gs over commercially available PEEK and PEKK due to the incorporation of the diphenyl moiety and amide linkages in the main chains. The polymers with 40-60 mol% BPBPPD had not only high T_gs of 183-189 °C, but also moderate T_ms of 314-328 °C, which are very suitable for the melt processing. These polymers had tensile strengths of 107.4-111.5 MPa, Young's moduli of 2.20-2.45 GPa, and elongations at break of 11.3-13.5% and exhibited high thermal stability and good resistance to organic solvents.     

Synthesis and properties of poly(aryl ether ketone)s containing both biphenylene moieties and sulfone linkages in the main chain

Two monomers, 4,4′‐bis(4‐phenoxybenzoyl)biphenyl (BPOBBP) and 4,4′‐diphenoxydiphenyl sulfone (DPODPS), were conveniently synthesized via simple synthetic procedures from readily available materials. A series of novel poly(aryl ether ketone)s containing both biphenylene moieties and sulfone linkages in the main chain were synthesized by the modified electrophilic Friedel‐Crafts acylation copolycondensation of isophthaloyl chloride (IPC) with a mixture of BPOBBP and DPODPS, over a wide range of BPOBBP/DPODPS molar ratios. The resulting polymers were characterized by Fourier transform infrared spectroscopy (FT‐IR), wide‐angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TGA), etc. The results indicated that the copolymers with 30 to 35 mol% DPODPS were semicrystalline and had remarkably increased glass transition temperatures (T_gs) over the conventional poly(ether ether ketone) (PEEK) and poly(ether ketone ketone) (PEKK) due to the incorporation of biphenylene units and sulfone linkages in the main chain. The copolymers with 30 to 35 mol% DPODPS had not only high T_gs of 176 to 177°C, but also moderate melting temperatures (T_ms) of 334 to 337°C, having good potential for the melt processing. The semicrystalline copolymers II to V had tensile strengths of 99.8 to 103.1 MPa, Young's moduli of 2.26 to 2.79 GPa, and elongations at break of 16.8 to 26.5% and exhibited outstanding thermal stability and good resistance to organic solvents. POLYM. ENG. SCI., 55:2140–2147, 2015. © 2015 Society of Plastics Engineers     

Synthesis and properties of novel phosphorus‐containing poly(ether ether ketone ketone)s

A novel monomer, bis[4‐(4‐fluorobenzoyl)phenyl]phenylphosphine oxide, was synthesized through the reaction of bis(4‐chloroformylphenyl) phenyl phosphine oxide with fluorobenzene. Three poly(ether ether ketone ketone)s derived from bis[4‐(4‐fluorobenzoyl)phenyl]phenylphosphine oxide and different aromatic bisphenols were prepared by aromatic nucleophilic substitution reactions. The resulting polymers had inherent viscosities in the range of 0.55–0.73 dL/g. The structures of the poly(ether ether ketone ketone)s were characterized with Fourier transform infrared and ¹H‐NMR. Thermal analysis indicated that the glass‐transition temperatures of the poly(ether ether ketone ketone)s were higher than 200°C, and the 5% weight loss temperatures in nitrogen were higher than 463°C. All the polymers showed excellent solubility in polar solvents such as N‐methyl‐2‐pyrrolidone, dimethylformamide, and dimethylacetamide and could also be dissolved in chlorinated methane. The polymers afforded transparent and flexible films by solvent casting. Organic phosphorous moieties also imparted good flame‐retardancy to the polymers. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Poly(ether ketone azomethane)s and poly(ether ketone imide)s containing naphthylene moieties

A new diamine monomer, 1,5-bis[4-(4-aminophenoxy)]benzoyl-2,6-dimethoxynaphthalene, was synthesized via a Friedel–Crafts acylation reaction followed by an aromatic nucleophilic substitution reaction. Six ether–ketone linked polymers, named as poly(ether ketone azomethane)s and poly(ether ketone imide)s, were successfully prepared through the polycondensations of the diamine monomer with dialdehydes and dianhydrides, respectively. These naphthylated polymers exhibited high T _g values (142–288 °C), due to their bulky and rigid chemical structure. Meanwhile, they showed good thermal stability and improved solubility. Typically, some of them were casted into thin flexible film and showed high moduli.     

Synthesis and characterization of organo‐soluble poly(ether ether ketone)s and poly(ether ether ketone ketone)s containing pendant pentadecyl chains

Poly(ether ether ketone)s and poly(ether ether ketone ketone)s containing pendant pentadecyl chains were synthesized by polycondensation of each of the two bisphenol monomers viz, 1,1,1‐[bis(4‐hydroxyphenyl)‐4′‐pentadecylphenyl]ethane and 1,1‐bis(4‐hydroxyphenyl)‐3‐pentadecyl cyclohexane with activated aromatic dihalides namely, 4,4′‐difluorobenzophenone, and 1,3‐bis(4‐fluorobenzoyl)benzene in a solvent mixture of N,N‐dimethylacetamide and toluene, in the presence of anhydrous potassium carbonate. Polymers were isolated as white fibrous materials with inherent viscosities and number average molecular weights in the range 0.70–1.27 dL g^?1 and 76,620–1,36,720, respectively. Poly(ether ether ketone)s and poly(ether ether ketone ketone)s were found to be soluble at room temperature in organic solvents such as chloroform, dichloromethane, tetrahydrofuran, and pyridine and could be cast into tough, transparent, and flexible films from their solutions in chloroform. Wide angle X‐ray diffraction patterns exhibited a broad halo at around 2θ = ～ 19° indicating that the polymers containing pentadecyl chains were amorphous in nature. In the small‐angle region, diffuse reflections of a typically layered structures resulting from the packing of pentadecyl side chains were observed. The temperature at 10% weight loss, obtained from TG curves, for poly(ether ether ketone)s and poly(ether ether ketone ketone)s were in the range 416–459°C, indicating their good thermal stability. A substantial drop in glass transition temperatures (68–78°C) was observed for poly(ether ether ketone)s and poly(ether ether ketone ketone)s due to “internal plasticization” effect of flexible pendant pentadecyl chains. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Synthesis and properties of novel organosoluble aromatic poly(ether ketone)s containing pendant methyl groups and sulfone linkages

Several novel aromatic poly(ether ketone)s containing pendant methyl groups and sulfone linkages with inherent viscosities of 0.62–0.65 dL/g were prepared from 2‐methyldiphenylether and 3‐methyldiphenylether with 4,4′‐bis(4‐chloroformylphenoxy)diphenylsulfone and 4,4′‐bis (3‐chloroformylphenoxy)diphenylsulfone by electrophilic Friedel–Crafts acylation in the presence of N,N‐dimethylformamide with anhydrous AlCl₃ as a catalyst in 1,2‐dichloroethane. These polymers, having weight‐average molecular weights in the range of 57,000–71,000, were all amorphous and showed high glass‐transition temperatures ranging from 160.5 to 167°C, excellent thermal stability at temperatures over 450°C in air or nitrogen, high char yields of 52–57% in nitrogen, and good solubility in CHCl₃ and polar solvents such as N,N‐dimethylformamide, dimethyl sulfoxide, and N‐methyl‐2‐pyrrolidone at room temperature. All the polymers formed transparent, strong, and flexible films, with tensile strengths of 84.6–90.4 MPa, Young's moduli of 2.33–2.71 GPa, and elongations at break of 26.1–27.4%. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

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     

Synthesis and characterization of novel copolymers of poly(ether ketone ketone) and poly(ether ketone sulfone imide)

A new monomer containing sulfone and imide linkages, bis{4-[4-(p-phenoxyphenylsulfonylphenoxy)benzoyl]-1,2-benzenedioyl}-N,N,N′,N′-4,4′-diaminodiphenyl ether (BPSPBDADPE), was prepared by the Friedel–Crafts reaction of bis(4-chloroformyl-1,2-benzenedioyl)-N,N,N′,N′-4,4′-diaminodiphenyl ether with 4,4′-diphenoxydiphenyl sulfone. Novel copolymers of poly(ether ketone ketone) and poly(ether ketone sulfone imide) were synthesized by electrophilic Friedel–Crafts solution copolycondensation of terephthaloyl chloride with a mixture of DPE and BPSPBDADPE. The polymers were characterized by different physico-chemical techniques. The polymers with 10–25?mol% BPSPBDADPE are semicrystalline and had increased T _gs over commercially available PEEK and PEKK (70/30) due to the incorporation of sulfone and imide linkages in the main chains. The polymer IV with 25?mol% BPSPBDADPE had not only high T _g of 194?°C but also moderate T _m of 338?°C, having good potential for melt processing and exhibited high thermal stability and good resistance to common organic solvents.     

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     

Crystallization behavior and mechanical properties of poly(aryl ether ether ketone)/poly(ether imide) blends

Crystallinity and mechanical properties of blends with different amounts of semicrystalline poly(aryl/ ether ether ketone) (PEEK) and amorphous poly(ether imide) (PEI) polymers have been studied. The blends, prepared by melt mixing, have been investigated by differential scanning calorimeter (DSC) to analyze the miscibility between the components and the final crystalline content. Moreover, for the 20/80 PEEK/PEI blend, crystallization in dynamic and isothermal conditions has been carefully investigated in order to find proper conditions for maximum development of crystallinity. Mechanical tests (static and dynamic) have been performed to evaluate the properties of the as-molded and crystallized blends and to compare them with those of crystalline PEEK and amorphous PEI neat resins. Finally, a few SEM observations have been performed to compare the fractured surface of the blend with those of the pure constituents.     

Synthesis and properties of poly(aryl ether sulfone ether ketone ketone) (PESEKK)

4,4′‐bis(Phenoxy)diphenyl sulfone (DPODPS) was synthesized by reaction of phenol with bis(4‐chlorophenyl) sulfone in tetramethylene sulfone in the presence of NaOH. Two poly(aryl ether sulfone ether ketone ketone)s (PESKKs) with high molecular weight were prepared by low temperature solution polycondensation of DPODPS and terephthaloyl chloride (TPC) or isophthaloyl chloride (IPC), respectively, in 1,2‐dichloroethane and in the presence of aluminum chloride (AlCl₃) and N‐methylpyrrolidone (NMP). The resulting polymers were characterized by various analytical techniques, such as FT‐IR, ¹H‐NMR, DSC, TG, and WAXD. The results show that the T_g and T_d of PESEKKs are much higher, but its T_m is lower than those of PEKK. The other results indicate that PESEKKs exhibit excellent thermostabilities at 300 ± 10°C. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 489–493, 2005     

Synthesis and gas transport properties of novel poly(aryl ether ketone)s with branched structure

Poly(aryl ether ketone)s (PAEKs) based on 2‐(3′‐trifluoromethylphenyl) hydroquinone and 4,4′‐difluorobenzophenone were synthesized and characterized in the presence or absence of 2,4′,6‐trifluorobenzophenone (BB′₂ monomer). The influence of the incorporation of a branched structure (BB′₂ monomer) on the gas transport properties of PAEKs was investigated. The results showed that PAEKs with a branched structure possess a higher permeability and selectivity than PAEKs without a branched structure. Moreover, improvements in the permeability and selectivity were enhanced with increasing content of BB′₂ monomer. This synergistic effect on permeability and selectivity was mainly due to the higher fractional free volume and the unique size and distribution of free volume holes arising from the incorporation of the branched structure. © 2013 Society of Chemical Industry     

Synthesis and properties of organic soluble semicrystalline poly(aryl ether ketone)s copolymers containing phthalazinone moieties

A series of poly(aryl ether ketone)s (PAEK) copolymers containing phthalazinone moieties were synthesized by modest polycondensation reaction from 4‐(4‐hydroxyl‐phenyl)‐(2H)‐phthalazin‐1‐one (DHPZ), hydroquinone (HQ), and 1,4‐bis(4‐fluorobenzoyl)benzene (BFBB). The T_g values of these copolymers ranged from 168 to 235°C, and the crystalline melting temperatures varied from 285 to 352°C. By introducing phthalazinone moieties into the main chain, the solubility of these copolymers was improved in some common polar organic solvents, such as chloroform (CHCl₃), N‐methyl‐2‐pyrrolidinone (NMP), nitrobenzene (NB) and so on. The values of 5% weight loss temperatures were all higher than 510°C in nitrogen. The crystal structures of these copolymers were determined by wide‐angle X‐ray diffraction (WAXD), which revealed that they were semicrystalline in nature, and the crystal structure of these copolymers was orthorhombic, equal to poly(ether ether ketone ketone)s. As phthalazinone content in the backbone varied from 0 to 40 mol % (mole percent), the cell parameters of these copolymers including the a, b, and c axes lengths ranged from 7.76 to 7.99 Å, 6.00 to 6.14 Å, and 10.10 to 10.19 Å, respectively. The degree of crystallinity (via differential scanning calorimetry) decreased from 37.70% to 16.14% simultaneously. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 1744–1753, 2007     

Synthesis and properties of thio‐containing poly(ether ether ketone)s

A series of thio‐containing poly(ether ether ketone) (PEESK) polymers was synthesized by the introduction of thio groups from 4,4′ thiodiphenol (TDP) into the poly(ether ether ketone) (PEEK) structure via reaction between the phenol and aromatic fluoride groups. The effect of the thio groups on the properties of the PEESK materials was investigated. Differential scanning calorimetry (DSC) analysis and X‐ray diffraction (XRD) patterns show a depression in the crystallinity of the PEESKs with incorporation of the content of thio groups in the backbones. The crystalline structure was identified as an orthorhombic structure with lattice constants of a = 7.52 Å, b = 5.86 Å and c = 10.24 Å for all crystallizable PEESKs. The crystalline structures of the thio‐containing PEEK polymers were the same as that of the neat PEEK, which means the thio‐containing block in the whole thio‐containing PEEK molecule is almost excluded from the crystalline structure and the crystals are completely formed by ‘non‐thio’ blocks only. Due to the glass transition temperature (T_g) and melting temperature (T_m) depression with increase in the TDP content in the reaction system, the processability of the resultant thio‐containing PEEKs could be effectively improved. Copyright © 2004 Society of Chemical Industry     

Crosslinkable poly(aryl ether ketone)s containing pendant phenylethynyl moieties: Synthesis, characterization and properties

A novel phenylethynyl-contained bisphenol monomer, (2,5-dihydroxyphenyl)(4-(2-phenylethynyl)phenyl)methanone (PEBP), has been synthesized and characterized. The resultant monomer was copolymerized with hydroquinone and 4,4′-difluorobenzophenone by means of an aromatic nucleophilic substitution reaction to provide a series of crosslinkable poly(aryl ether ketone)s containing pendant phenylethynyl moieties (PE-PAEKs). The solubility of PE-PAEKs tended to be improved with the increase in PEBP content. Wide-angle X-ray diffraction (WAXD) results showed that introduction of bulky pendant groups into molecular chains led to decrease in crystallinity. PE-PAEKs were successfully cured upon heating. Dynamic mechanical analysis (DMA) results indicated that the glass-transition temperature (T_g) of the cured PE-PAEKs was increased. Thermogravimetric analysis (TGA) results implied that the thermal stability of the cured PE-PAEKs was excellent.     

Synthesis and properties of poly(aryl ether ketone) copolymers containing 1,5-naphthalene moieties

Poly(aryl ether ketone) copolymers possessing various compositions of 1,5-naphthalene and 1,4-phenylene moieties were prepared by the reaction of 4,4′-difluorobenzophenone with hydroquinone (HQ) and 1,5-dihydroxynaphthalene (DHN) in the presence of sodium carbonate and potassium carbonate in diphenyl sulfone. The synthesized copolymers were characterized by FT-IR spectra, differential scanning calorimetry, and thermogravimetric analysis. Thermal analyses of the copolymers showed that the glass transition temperature increased, while the melting temperature and 2.5% weight loss temperature decreased with increasing content of 1,5-naphthalene moieties. For the copolymers synthesized with the molar fraction of DHN in the dihydroxy monomers (DHN, HQ) being over 0.4, no cold crystallization temperature and melting temperature were detected, indicating that these copolymers are almost amorphous. The crystal structure of the copolymers with the molar fraction of DHN being not higher than 0.2 is rhombic, equal to poly(ether ether ketone).     

Synthesis and properties of novel copolymers of poly(ether ketone ether ketone ketone) and poly(ether ketone ketone ether ketone ketone) containing 1,4‐naphthylene moieties

A new monomer, 1,4‐bis(4‐phenoxybenzoyl)naphthalene (BPOBN), was conveniently synthesized via a simple synthetic procedure from readily available materials. A series of novel copolymers of poly(ether ketone ether ketone ketone) and poly(ether ketone ketone ether ketone ketone) containing 1,4‐naphthylene moieties were prepared by the Friedel‐Crafts acylation solution copolycondensation of terephthaloyl chloride (TPC) with a mixture of BPOBN and 4,4′‐diphenoxybenzophenone (DPOBPN), over a wide range of BPOBN/DPOBPN molar ratios, in the presence of anhydrous AlCl₃ and N‐methylpyrrolidone in 1,2‐dichloroethane. The copolymers with 10–40% BPOBN are semicrystalline and had remarkably increased T_gs over the conventional PEEK and PEKK due to the incorporation of 1,4‐naphthylene moieties in the main chains. The copolymers with 30–40 mol% BPOBN had not only high T_gs of 176–177°C, but also moderate T_ms of 332–338°C, which are suitable for the melt processing. These polymers had tensile strengths of 101.5–104.7 MPa, Young's moduli of 2.49–2.65 GPa, and elongations at break of 13.3–15.7% and exhibited high thermal stability and excellent resistance to organic solvents. POLYM. ENG. SCI., 56:566–572, 2016. © 2016 Society of Plastics Engineers     

Sulfonated poly(aryl ether ketone)s

Several kinds of commercially available polymers of the type poly(oxy-1,4-phenylenecarbonyl-1,4-phenylene) were sulfonated by reaction with mixtures of sulfuric acid and oleum. The ether/carbonyl group ratio of the polymer chain varied from 0.67 to 2.0. With decreasing amounts of ether links in the polymer backbone the sulfonation is hindered and the reaction conditions have to be stronger. To yield the same degree of sulfonation, the sulfuric trioxide concentration of the reaction mixture has to be increased. The achievable degree of substitution is limited, in general, to one sulfonate group per substitutable unit (oxy-phenylene-oxy- or oxy-phenylene-carbonyl unit). In dependence on the polymer structure, polymers with contents of sulfonate groups between 1.2 and 2.0 meq·g^–1 polymer are well soluble in dimethylformamide or N-methylpyrrolidone and it is possible to produce membranes with permselectivities >96% and electrical resistances < 2 Ω cm^–2. The sulfonated polymers were characterized by viscosimetry, sedimentation analysis and ¹³C NMR spectroscopy.     

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     

Synthesis and characterization of novel poly(aryl ether ketone)s containing both biphenylene and 1,4-naphthylene moieties

A novel epoxidized hydroxyl-terminated hyperbranched polymer (HPEEX) was formulated from epichlorohydrin and hydroxy-terminated hyperbranched polyester (HPE) based on trimethylol propane (TMP) and AB₂ monomer. The obtained HPEEX was characterized with FT-IR, ¹HNMR spectroscopy, TG, WAXD and GPC analysis. Results showed that the HPEEX was formulated as expected and its molecular weight and intrinsic viscosity were 3,789 g/mol and 3.96 mL/g, respectively. Meanwhile, the HPEEX was used as cross-linking agent in the preparation of waterborne epoxy resins. Performance of the HPEEX modified epoxy resin aqueous (EP-H) dispersions and their films was evaluated by various tests. It was found that with incorporation of hyperbranched polymer into the epoxy macromolecular chain, the EP-H films exhibited excellent hardness and water-proof performance: the hardness was as high as 96 (Shore A), and the contact angle of water on the surface of this kind of film was as high as 71°, resulting from branched structure, higher functionality of HPEEX, better cross-linking density and large number of hydrogen bonding in this epoxy system.