Phthalazinone Ether Ketone Research Articles

High-Temperature Poly(phthalazinone ether ketone) Thin Films for Dielectric Energy Storage

The synthesis and characterization of poly(phthalazinone ether ketone) (PPEK) for high-temperature electric energy storage applications is described. It was found that PPEK displayed excellent stability of the dielectric properties over a broad frequency and temperature range. Little change in the breakdown field and discharge time has been observed in PPEK with the increase of temperature up to 190 degrees C. A linear correlation between the AC conductance and the angular frequency implied that the hopping as a dominant conduction process contributed to the dielectric loss. Superior energy densities, remarkable breakdown strengths, and fast discharge speeds have been demonstrated in PPEK at various temperatures.

Functionalization of multi-walled carbon nanotubes with non-reactive polymers through an ozone-mediated process for the preparation of a wide range of high performance polymer/carbon nanotube composites

Polymer chains are chemically bonded to multi-walled carbon nanotubes (MWCNTs) through an ozone-mediated process. Four polymers, poly(vinylidene fluoride) (PVDF), polysulfone (PSF), poly(2,6-dimethylphenylene oxide), and poly(phthalazinone ether ketone) are used to demonstrate this MWCNT functionalization. MWCNT–polymer hybrids are characterized by Fourier transform infrared spectroscopy, Raman spectrometry, X-ray photoelectron spectrometry, and high-resolution transmission electron microscopy. This approach provides a general method of preparation of matrix–polymer-modified MWCNTs to be used in the preparation of polymer/MWCNT composites. Compared to pristine MWCNTs and PSF-modified MWCNTs, PVDF-modified MWCNTs are more efficient additives to enhance the mechanical strength and electrical conductivity of PVDF. Therefore, matrix–polymer-modified MWCNTs are relatively attractive in the preparation of high performance polymer/MWCNT composites.

Cure kinetics, phase behaviors, and fracture properties of bismaleimide resin toughened by poly(phthalazinone ether ketone)

AbstractPoly(phthalazinone ether ketone)s (PPEK) were used to toughen bismaleimide (BMI) resin composed of 4,4′‐bismaleimidodiphenyl methane (BMDM) and O,O′‐diallyl bisphenyl A (DABPA). Dynamic differential scanning calorimetry (DSC) of the blends was carried out for kinetic analysis of the curing reaction. The reaction activation energy indicated that the reaction mechanism remained the same even after the incorporation of PPEK. The reaction‐induced phase separation process in BMI/PPEK blends was investigated by optical microscopy (OM). The primary phase structure of the blends was fixed at the early stage of phase separation, and a secondary phase separation was observed as a result of the high viscosity of the blends. Scanning electron microscope (SEM) graphs showed that the morphology of the cured resin changed from a dispersed structure to a phase‐inverted structure with the increase of PPEK content. Compared with the neat resin, the fracture toughness of the modified resin exhibits a moderate increase when PPEK was incorporated. Several toughening mechanisms, such as local plastic deformation, crack deflection, and branches, presumably took part in improving the toughness of BMI/PPEK blends on the basis of the morphology. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers

Impregnated membranes for direct methanol fuel cells at high methanol concentrations

Sulfonated poly(phthalazinone ether ketone) (SPPEK) impregnated Solupor ® microporous film (SPPEK–PE) and pure SPPEK membranes with two different ion-exchange capacities (IECs) were prepared and characterized for use in DMFC applications. Swelling, proton conductivity, diffusion and DMFC experiments were performed at various methanol concentrations to understand the effect of impregnation of an ion-conductive polymer membrane to the fuel cell performance. Impregnating SPPEK into PE decreases swelling degree and methanol permeability of the membranes, but at the same time the proton conductivity. Unlike perfluorinated membranes, SPPEK–PE shows an increase in its DMFC performance at high methanol concentration and that makes it more attractive for mobile DMFC applications where high methanol concentrations are needed to compete with Li-ion batteries.

Synthesis of fluoro-containing sulfonated poly(phthalazinone ether ketone ketone)s and their properties as PEM in PEMFC and DMFC

A series of sulfonated poly(ether ketone ketone)s (SPPFEKKs) containing both of phthalazinone and hexafluoroisopropylidene moieties were synthesized by direct nucleophilic polycondensation reaction from 4-(4-hydroxyphenyl)-1(2H)-phthalazinone (DHPZ), 4,4-hexafluoroisopropylidene-diphenol (BPAF), 1,4-bi(4-fluorobenzoyl) benzene (DFKK) and 1,4-bi(3-sodium sulfonate-4-fluorobenzoyl) benzene (SDFKK). The obtained SPPFEKKs had high molecular weight with inherent viscosity ranged from 1.29 to 1.53 dL/g and their chemical structure was characterized by FT-IR and 1H NMR. The ionic membranes of SPPFEKKs showed high proton conductivity, for instance, SPPFEKK-120 (DS = 1.20) demonstrated 1.0 × 10 −1 S/cm proton conductivity at 95 °C, which was very close to that of Nafion ®117. All the SPPFEKK membranes exhibited methanol permeability lower than 2.76 × 10 −7 cm 2/s, which was much lower than that of Nafion ®117 (2.38 × 10 −6 cm 2/s). These copolymers also showed excellent thermal stability and good solubility in aprotic polar organic solvents. The ionic membranes of SPPFEKK demonstrated tensile strength varied from 57 to 69 MPa depending on their DS.

Alkaline polymer electrolyte membranes from quaternized poly(phthalazinone ether ketone) for direct methanol fuel cell

AbstractQuaternized poly(phthalazinone ether ketone)s (QPPEK)s were synthesized by the chloromethylation and quaternization of poly(phthalazinone ether ketone) (PPEK) with chloromethyl methyl ether in 98% concentrated sulfuric acid and following trimethylamine. The presence of CH2Cl groups in chloromethylated PPEK was confirmed by 1H‐NMR. An alkaline QPPEK membrane was prepared and its thermal and mechanical properties were tested. The alkaline QPPEK membrane had a methanol permeability 6.57 × 10−7 cm2/s and the highest anion conductivity 1.14 × 10−2 S/cm. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008

Polymer electrolyte membranes derived from modified poly(phthalazinone ether ketone) for fuel cell applications

The sulfonated poly(phthalazinone ether ketone) (SPPEK) membrane and quaternized poly(phthalazinone ether ketone) (QPPEK) membrane were prepared by the casting method from corresponding materials. Suitable thermal and mechanical properties of modified PPEK membranes were proved by thermogravimetry analysis and tensile machine. The ionic conductivities and methanol permeabilities of the two kinds of membranes were tested and compared with each other. The proton conductivity of SPPEK membrane and the hydroxide ion conductivity of QPPEK membrane reached respectively the maximum of 0.031 S/cm at 95 °C and of 0.014 S/cm at 80 °C under 100% relative humidity. Both the methanol permeabilities at room temperature were lower than that of Nafion117.

Preparation and characterization of poly(phthalazinone ether ketone)/SiO2 hybrid composite thin films with low friction coefficient

Organic–inorganic poly(phthalazinone ether ketone) (PPEK)/SiO2 hybrid composite thin films were prepared by the dip-coating method on pre-cleaned glass substrates. The covalent bonds between organic and inorganic phases were introduced by an in-situ O-acylation reaction of isocyanatopropyltriethoxysilane (ICPTES) with the borohydride-reduced PPEK forming a polymer bearing triethoxysilyl groups. Theses groups were subsequently hydrolyzed with tetraethoxysilane (TEOS) and allowed to form a network via a sol–gel process. The polymer hybrid composite exhibited good thermal stability and a higher glass transition temperature as compared with the pure resin. Atomic force microscope, water contact angle measurement and scanning electron microscope were used to characterize the polymer hybrid thin films. The tribological experiment showed that the films have very low friction coefficient (about 0.1) and good anti-wear properties, without failure even after sliding for 18,000 s under modest loads. The improved tribological properties of the modified substrate were attributed to good adherence of PPEK/SiO2 hybrid films on the substrate and synergy of both PPEK matrix and silica particles.

Synthesis, characterization and optical properties of cross-linkable poly(phthalazinone ether ketone sulfone)

Cross-linkable poly(phthalazinone ether ketone sulfone) bearing tetrafluorostyrene groups (PPEKS–FSt) has been prepared by copolycondensation reaction for optical waveguide applications. The resulting amorphous polymer exhibits good solubility in some common polar organic solvents (e.g., N,N′-dimethylacetamide, N-methyl-2-pyrrolidinone, chloroform) at room temperature, and can be easily spin-coated into thin films with good optical quality. The glass transition temperature (Tg) and the temperature of 1% weight loss (1% Td) are 261°C and 494°C, respectively, which could be further increased by 31°C and 14°C upon thermal cross-linking. The cross-linked polymer thin films exhibit high refractive index (∼1.65, TE mode), high thermo-optic coefficient value (dn/dT) (−1.455×10−4/°C, TE mode), low optical loss (less than 0.24dB/cm at 1310nm) and relatively low birefringence (∼0.007).

Modified poly(phthalazinone ether ketone) membranes for direct methanol fuel cell

AbstractSulfonated poly(phthalazinone ether ketone)s (SPPEK)s were synthesized by the modification of poly(phthalazinone ether ketone) (PPEK) with 98% concentrated sulfuric acid or 98% concentrated sulfuric acid and chlorosulfonic acid mixture at 80–100°C. The presence of sulfonic acid groups in SPPEKs was confirmed by Fourier transform infrared (FTIR) analysis and nuclear magnetic resonance (NMR), and the DSs were determined by Energy Dispersive X‐Ray (EDX). A blend membrane of No. 21 SPPEK and phosphotungstic acid (PWA) was prepared. The methanol permeabilities of SPPEK and blend membranes were about 20 times lower than that of Nafion117 at room temperature. The direct methanol fuel cell (DMFC) test of 2 M methanol solution and air breathing showed that the blend membrane had a better performance than that of the Nafion117. Copyright © 2007 John Wiley & Sons, Ltd.

Synthesis and characterization of trimethoxysilyl-functionalized poly(phthalazinone ether ketone)

A novel alkoxysilyl-functionalized poly(phthalazinone ether ketone) (PPEK) was prepared for the boundary lubricant application in micro-electro-mechanical system (MEMS). The synthesis of functionalized PPEK was started from the hydroxylation of PPEK, then following with the corresponding ring-opening reaction of 3-glycidoxypropyltrimethoxysilane (GPTMS). The structures of the functional PPEK were confirmed by FTIR, 1H NMR, 29Si NMR, and UV–vis spectrum.

Synthesis and characterization of cross‐linkable poly(phthalazinone ether ketone)s

AbstractA novel class of crosslinkable poly(phthalazinone ether ketone)s with relative high molecular‐weight and good solubility were successfully synthesized by the copolymerization of bisphthalazinone containing monomer, 3,3′‐diallyl‐4,4′‐dihydroxybiphenyl and 4,4′‐di‐ fluorobenzophenone. The synthesized polymers with inherent viscosities in the range of 0.42 to 0.75 dL/g can form flexible and transparent membranes by casting from their solution. The crosslinking reaction of these polymers can be carried out by thermally curing of the virgin polymers in or without the presence of crosslinking agent. The experimental results demonstrated that the crosslinking reaction also occurred to some extent during the polymerization. The crosslinked polymers exhibited equivalent glass transition temperature (Tg) at lower crosslinking density, and showed higher Tg than virgin polymers at higher crosslinking density. The crosslinked high‐temperature polymer can be used as the base material for high temperature adhesive, coating, enamel material, and composite matrices. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007

Proton exchange membranes modified with sulfonated silica nanoparticles for direct methanol fuel cells

Nanocomposite proton exchange membranes were prepared from sulfonated poly(phthalazinone ether ketone) (sPPEK) and various amounts of sulfonated silica nanoparticles (silica-SO 3H). The use of silica-SO 3H compensates for the decrease in ion exchange capacity of membranes observed when non-sulfonated nano-fillers are utilized. The strong –SO 3H/–SO 3H interaction between sPPEK chains and silica-SO 3H particles leads to ionic cross-linking in the membrane structure, which increases both the thermal stability and methanol resistance of the membranes. The membrane with 7.5 phr of silica-SO 3H (phr = g of silica-SO 3H/100 g of sPPEK in membranes) exhibits low methanol crossover, high bound-water content, and a proton conductivity of 3.6 fold increase to that of the pristine sPPEK membrane.

Hybrid proton exchange membranes based on sulfonated poly(phthalazinone ether ketone) and zirconium hydrogen phosphate

AbstractSulfonated poly(phthalazinone ether ketone)s (SPPEKs) and zirconium hydrogen phosphate (ZrP) hybrid membranes for direct methanol fuel cells (DMFCs) were prepared by the impregnation method and direct blending method. The physicochemical properties of these hybrid membranes were studied by means of field‐emission scanning electron microscope (FSEM), X‐ray diffraction (XRD) analysis, and thermogravimetry analysis (TGA). For the hybrid membranes prepared from impregnation procedure, the highest proton conductivity could reach 0.074 S/cm at 80°C under 100% relative humidity and the methanol permeability at room temperature is more than 10 times lower than that of Nafion 117. Copyright © 2007 John Wiley & Sons, Ltd.

Novel sulfonated poly(phthalazinone ether ketone) ionomers containing benzonitrile moiety for PEM fuel cell applications

A series of benzonitrile-containing sulfonated poly(phthalazinone ether ketone) ionomers were successfully synthesized via the direct copolymerization of benzonitrile-containing bis(phthalazinone), 3,3′-sulfonated-4,4′-difluorodiphenyl ketone and 4,4′-difluoro-diphenyl ketone. The sulfonation degrees can been readily controlled by changing the feed ratio of monomers. The resulting sulfonated polymers with inherent viscosity ranging from 0.45 to 0.72 dL g −1 were characterized by 1H NMR and other technologies. These sulfonated polymers had good solubility in polar aprotic solvents and afforded tough and ductile membranes by casting from DMAc solution at 60 °C. Due to the specially designed chemical structures, the membranes showed excellent thermal and oxidative stabilities. Thermogravimetric analysis (TGA) traces demonstrated that all the sulfonated polymers exhibited good thermal stability with initial weight loss > 220 °C. The membranes exhibited superior oxidative and hydrolytic stabilities as evidenced by Fenton's reagent. The membranes showed moderate water uptake in low sulfonation degree (≦1.2), and the proton conductivity of the membrane with sulfonation degree of 1.2 was 1.03 × 10 −3 S cm −1 at 25 °C and 100% relative humidity. The proton conducting and other properties as a membrane can be tailorated by controlling the sulfonation degree.

Copolymerization and blending of poly(phthalazinone ether ketone)s to improve their melt processability

AbstractThe melt processability of phthalazinone‐containing poly(aryl ether)s (PAEs) was improved through copolymerization and blending. Poly(phthalazinone ether ketone) (PPEK) copolymers containing phthalazinone and bisphenol‐A (BPA) moieties were synthesized through nucleophilic substitution polycondensation. The PPEK copolymers exhibited high glass transition temperatures, excellent thermooxidative properties, good mechanical properties and improved solubility, all of which can be tailored by changing the molar ratio of phthalazinone to bisphenol monomers. The rheological investigation indicated that the incorporation of the flexible BPA moiety into the main chain lowered the melt viscosity of the copolymers. To improve the melt processability further, polymer blends of a PPEK copolymer/polycarbonate (PC) were prepared. The results suggested that blending is an effective approach for improving the melt processability of phthalazinone‐containing PAEs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 2575–2580, 2007

Modified sulfonated poly(phthalazinone ether ketone) membranes with inorganic particles for potential applications in PEMFCs

AbstractComposite membranes of sulfonated poly (phthalazinone ether ketone)s (SPPEK)s and Zirconium hy drogen phosphate (ZrP) or 12‐phosphotungstic acid (PWA) were prepared by direct blending method. The physicochemical properties of these composite membranes were studied through Fourier transform infrared attenuated total reflection (FTIR‐ATR) spectroscopy, field‐emission scan ning electron microscope (FSEM), X‐ray diffraction (XRD) and thermogravimetry analysis (TGA). The SPPEK/PWA composite membranes showed better properties, whose highest proton conductivity could reach 0.17 S/cm at 80°C under 100% relative humidity (R.H.). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3972–3977, 2006

Composite membranes of sulfonated poly(phthalazinone ether ketone) doped with 12-phosphotungstic acid (H 3PW 12O 40) for proton exchange membranes

Sulfonated poly(phthalazinone ether ketone) (SPPEK) and 12-phosphotungstic acid (PWA) composite membranes were prepared by the casting procedure, using SPPEK solution blended with PWA. The physicochemical properties of these composite membranes were studied by means of field-emission scanning electron microscopy (FSEM), X-ray diffraction (XRD) analysis, thermogravimetry analysis (TGA) and Fourier transform infrared attenuated total reflection (FTIR-ATR) spectroscopy. The PWA particles in composite membranes are stable due to the interaction between SO 3H group of SPPEK and PWA particles. The proton conductivity of the composite membrane containing 10% PWA reaches the maximum of 0.17 S/cm at 80 °C under 100% relative humidity.

Synthesis and properties of poly(phthalazinone ether ketone ketone)s containing pendent methyl groups

A new class of poly(phthalazinone ether ketone ketone)s has been prepared by aromatic nucleophilic displacement polycondensation from an activated dichloride monomer 1 and several phthalazinone containing bisphenol-like monomers 2a– c. The formation of the polymers was confirmed by FT-IR and 1H NMR spectra, and the synthesized polymers 3a– c have good solubility in common organic solvents, high glass transition temperatures ( T gs) in range of 239–255 °C and excellent thermal stability. Moreover, tough, flexible and transparent thin films can be readily prepared by both spin coating and solution casting approach. Good solubility in common organic solvents coupled with salient thermal stability demonstrates this class of polymers could be excellent candidate for high performance polymers.

Sulfonated copoly(phthalazinone ether ketone nitrile)s as proton exchange membrane materials

Sulfonated poly(phthalazinone ether ketone nitrile) copolymers (SPPEKN) were prepared by copolymerization of disodium 3,3′-disulfonate-4,4′-difluorobenzophenone (SDFB-Na), 2,6-difluorobenzonitrile (2,6-DFBN), and 4-(4-hydroxyphenyl)-1(2 H)-phthalazinone (DHPZ) at 160 °C in N-methyl-2-pyrrolidione containing anhydrous potassium carbonate. The polymerization reactions proceeded smoothly and in high yield giving high molecular weight SPPEKN copolymers with different sulfonic acid content (SC) values. The polymer structures were defined by 1H NMR and FT-IR. Membrane films of SPPEKN copolymers in both salt and acid forms, prepared at SDFB-Na to 2,6-DFBN feed ratios up to 60/40 mol/mol, were cast from the N, N-dimethylacetamide (DMAc) polymer solutions. The presence of highly polar nitrile groups are expected to increase inter-chain molecular forces, contributing to the observed reduction in water swelling over previously prepared sulfonated poly(phthalazinone ether ketone) (SPPEK) copolymers. Membranes containing nitrile groups are expected to show improved adhesion between polymer and catalyst when utilized in a fuel cell. All SPPEKN copolymers exhibited tensile strength higher than that of Nafion ®117. The proton conductivities of acid form SPPEKN copolymers (SPPEKNH)s, prepared at the sulfonated/unsulfonated monomer feed ratio above 0.35 mol/mol, were around 10 −1 S/cm at 80 °C, which is close to or higher than that of Nafion ®117 under same measurement conditions.