Poly Aryl Ether Ketone Research Articles

Nanomechanical Properties of a Bicomponent Epoxy Resin via Blending with Polyaryletherketone

In order to investigate the nanomechanical behaviors and nanotribological properties of bicomponent epoxy resin (BE) blends, which were filled with thermoplastic polyaryletherketone (PAEK) powders, nanoindentation and nanoscratch tests were performed. The brittle fractured morphologies of bicomponent epoxy resin blends were studied. The microhardness and elastic modules of the materials were measured using the nanoindentation technology. The hardness, elastic modulus, and other mechanical properties of materials on a nanoscale were determined. Nanoindentation and scratch experiments showed that the indentation response is dominated by plastic deformation. The microhardness is the lowest as the content of PAEK powders is increased to 30 parts per hundred parts of resin (phr), while that of the neat bicomponent epoxy resin specimen is the highest. Furthermore, the pristine bicomponent epoxy resin (BE) exhibited better load-carrying and indentation recovery capacity than the other three samples. The nanoscratch results indicate that the frictional coefficient of the BE/PAEK-30 blend is the lowest, and while that of the pristine bicomponent epoxy resin is the highest, with better scratch/wear resistance.

INTERACTION IN POLYARYLATE – POLY(ARYLENE ETHER KETONE) MIXTURE AT HIGH-TEMPERATURE PROCESSING

Methods of modifying polyarylate based on bisphenol A and mixture of iso- and terephthalic acids by a representative of a promising class of polymers — polyarylene ether ketone have been discussed in this article. Comparative thermomechanical and thermofriction tests of two grades of poly(arylene ether ketone)based on bisphenol A and 4,4'-difluorobenzophenone (PAEK-32 and PAEK-34) have been carried out. It has been established that PAEK-34 is the most suitable for modifying polyarylate, which is confirmed by its higher softening temperature and stable friction coefficient at elevated temperatures. The thermomechanical properties and molecular mass distribution of amorphous polyarylene ether ketone before and after pressing have been studied. It has been established that during processing of poly(arylene ether ketone) PAEK-34 it’s molecular weight increases from 123 to 178 thousand a.m.u. with simultaneous change in the character of the molecular mass distribution from bimodal to unimodal. At the same time, there is a sharp decrease in the content of the low molecular weight fraction from 23.32 to 7.2%. Theoretical compatibility of polyarethylene ether ketone PAEK-34 and polyarylate DV based on the theory of solubility of substances has been studied. It was established that mixtures of these polymers are compatible for any components’ ratio according to the calculation results. The thermomechanical characteristics of the mixtures obtained on the basis of polyarylate and polyarylene ether ketone have been evaluated. It has been established that the growth of heat resistance of the mixture during processing is caused by intermolecular interaction of components with the formation of new chemical compounds having a block-type copolymer structure. This was confirmed by the change in the nature of the molecular-mass distribution of the polymer mixture upon the transition of the pressing temperature from 260 °C to 300 °C. It was established that the optimal conditions for the realization of block-copolymer formation reaction are created at 300 °C.

Polyether-Ketones Based on 1,1-Dichloro-2,2-Di(3,5-Dibromo-4-Hydroxyphenyl) Ethylene

Basic properties of poly (arylene ether ketone) s based on 1,1-dichloro-2,2-di (3,5-dibromo-4-hydroxyphenyl) ethylene were synthesized and studied. Polyarylene ether ketones were obtained on the basis of 1,1-dichloro-2,2-di (3,5-dibromo-4-hydroxyphenyl) ethylene with increased heat - thermal and fire resistance of structural and film purposes.

Exploring the tribo-potential of nano and micron-sized particles of potassium titanate in PAEK based composite

Structural and mechanical integrity, as well as friction and wear performance of a composite designed for tribological application (hereafter called as tribo-composite) depends on a precise selection and potent combination of fillers, fibers, and polymer matrix along with right processing technique. Modern day research is primarily focused on exploring the suitability and potential of new ingredients, which are better than the conventional ones, in enhancing the friction and wear performance of a tribo-composite. In-depth laboratory scale study on the tribo-performance evaluation of these ingredients is a key to explore their potential and use at an industrial level. Particles of potassium titanate (KT) is one of such ingredients which helps in reducing wear of friction materials. However, its role in influencing the wear performance of anti-friction materials is still unexplored. In the present work, the potential of KT particles (10 wt%) in two sizes (micron and a combination of micrometer and nanometer, 7 + 3 wt%) has been evaluated. In all, three tribo-composites based on two fixed ingredients viz. polyaryletherketone (PAEK) and short glass fibers (GF-30 wt%) were developed. The first composite contained 10 wt% graphite, while the other two composites contained additional 10 wt% KT particles. It was observed that KT particles acted as a solid lubricant despite not having a layer-lattice structure. Tribo-composites with nanoparticles of KT as a filler proved more effective at severe sliding conditions (PVlimit 168 MPa m s−1) compared to that filled with micron-sized particles (PVlimit 112 MPa m s−1 respectively). Based on this study, it was concluded that KT proved as a filler having the potential to enhance the tribo-performance of PAEK based composites and nano-sized particles proved more efficient compared to the micro-sized one.

Optimization of wear behaviour of boron nitride filled polyaryletherketone composites by Taguchi approach

This research article intends to portray the act of boron nitride (BN) filler (0–30 wt%), functional load, sliding speed and sliding distance on the tribological wear conduct of polyaryletherketone (PAEK). The main purpose is to investigate the impact of the above mentioned factors on the specific wear rate (Ks). These composites are manufactured by methods for extrusion pursued by injection moulding procedure. Friction and wear failure information are gathered utilizing Pin-on-Disk wear test rig. At all tribo-test conditions, the friction coefficient (μ) and Ks diminishes up to 10 wt% of BN and after which it augments. Optimization of the tribological performance was directed by Taguchi plan of trials to investigate the Ks. The Ks of unfilled PAEK is in the order of 4.48 × 10−6 mm3 Nm−1, while the Ks of 10 and 30 wt% BN filled PAEK is 1.21 × 10−6 and 6.22 × 10−6 mm3 Nm−1 correspondingly. The best outcomes are seen at a BN stacking with 10 wt%. Sliding distance was found as the most persuasive factor influencing the wear conduct of PAEK-BN composites, other variables like load, filler wt% and sliding speed likewise had a segment to play in achieving the least Ks. Worn surface morphology was contemplated utilizing scanning electron microscopy.

Optimization of graphite contents in PAEK composites for best combination of performance properties

Graphite is one of the most widely used solid lubricants in both, anti-friction and friction materials. The influence of particles in the composite mainly depends on its size, amount, its combination with fibers and other fillers etc. No efforts were done to optimize the amount of graphite to achieve very low friction and wear. A series of Polyaryl ether ketone (PAEK) composites with GF (short glass fibers) and increasing amount of graphite particles (10, 15, 20 and 25 wt %) were developed and characterized for various properties such as physical, mechanical, thermal along with adhesive wear performance in severe operating conditions (high pressure and velocity (PV)). Inclusion of graphite led to deterioration in strength and modulus but increase in thermal conductivity. The composites showed very low μ (friction coefficient) in the range of 0.04 and K0 (specific wear rate) (∼2 × 10−16 m3/Nm). Composite with 15 wt % graphite proved to be significantly superior by showing highest PVlimit value (154 MPa m/s) and very low μ (0.04) and K0 (1.91 × 10−16 m3/Nm). The typical inferences were supported by various techniques such as Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), 3D profilometer, Raman spectroscopy on the worn surfaces.

Making a strong adhesion between polyetherketoneketone and carbon nanotube fiber through an electro strategy

High temperature thermoplastics are gaining popularity due to their superior toughness and durability. For a new member in the polyaryletherketone (PAEK) family, polyetherketoneketone (PEKK) has shown the highest melting temperature, up to 380 °C. Meanwhile, it requires a high temperature to improve the interfacial shear strength (IFSS) between PEKK and a fiber, toward advanced thermoplastic composites. Owing to the strong Joule heating in carbon nanotube (CNT) fibers, a more efficient strategy is designed to enhance the IFSS. Under the electro treatment, the surrounding PEKK starts the melting at the fiber surface, and even impregnates into the CNT assemblies. As a result, the interfacial interaction can be remarkably enhanced. The highest IFSS is up to 80.4 MPa for the electro-treated interface between a CNT fiber and PEKK, higher than the thermal-treated IFSS (52.5 MPa) and that between an aramid fiber and PEKK (59.8 MPa).

Structural, thermal and dielectric behavior of Polyaryletherketone (PAEK)/CaCu3Ti4O12 (CCTO) nanocomposite films

Polyaryletherketone (PAEK)/CaCu3Ti4O12 (CCTO) nanocomposite films with various (0, 1, 5, 10 and 20) weight % CCTO were fabricated via melt-compounding followed by film extrusion process. CCTO nanoceramics (nCCTO) with a crystallite size of about 30–100 nm were prepared from oxalate precursor route. Thickness of the fabricated films was in the range of 50–80 μm, and these films were characterized for their structural, thermal, and dielectric behavior. X-ray diffraction analyses showed the presence of peaks corresponding to both PAEK and CCTO with varying intensities. Fourier transform infrared (FTIR) studies revealed that the chemical structure of PAEK was unaltered by the incorporation of nCCTO. Melting temperature of pure PAEK was about 372 °C, which did not change significantly with the addition of nCCTO. Thermo-gravimetric analysis was carried out to study the thermal stability of these nanocomposites. Frequency independent dielectric behavior was observed in case of all nanocomposite films. Room temperature dielectric permittivity of PAEK (3.3 at 10 kHz) was enhanced with the addition of nCCTO, and for 20 wt% loading a value of 4.5 was achieved. Low values of dielectric loss (0.005–0.009) were obtained for all nanocomposite films at 10 kHz. These nanocomposites can be explored as possible dielectric materials for capacitor applications.

On the significant enhancement in the performance properties of PAEK composite by inclusion of a small amount of nano-mica particles

Abstract The paper reports on the comparative potential of nano-particles and micro-particles of mica in glass fiber reinforced Polyaryletherketone (PAEK) composite containing graphite (10 wt%). Very high PVlimit value (>100 MPa-m/s), very low specific wear rate (K0) (2–∼8 × 10−16 m3/Nm) along with very low friction coefficient (μ) (0.04–0.08), were exhibited by the composites. The PVlimit values of a nano-composite (NC) and micro-composite were 126 and 84 MPa m/s respectively. Friction and wear performance of a nono-composite was significantly better at lower PV conditions (40% lower in wear rate and 20% in friction). Worn surfaces were studied by scanning electron microscopy (SEM) and 3D profilometer, while the interaction of the constituents with a disc surface was investigated with the X-ray photoelectron spectroscopy (XPS).

On the Sliding Wear Behavior of PAEK Composites in Vacuum Environment

In the present study, the tribological behavior of polyaryletherketones (PAEKs) and their composites was investigated in air and vacuum environment. Polymer matrices were filled with either glass or carbon fibers and compared with a standard bearing material containing 10% carbon fiber (CF), 10% graphite, and 10% polytetrafluoroethylene (PTFE). The samples were tested in a pin-on-disk configuration under continuous sliding against a rotating steel disk (AISI 52100) at different sliding speeds. The results indicated that the tribological performance of these materials in vacuum depends on both compositions and test conditions. At low sliding speed, a very low friction and wear coefficients were obtained while at higher speed, severe wear occurred. In particular, CF filled composites showed excessive wear that led to the ignition after opening the vacuum chamber. Experimental results are discussed by analyzing the transfer film and wear debris.

Experimental investigation of the fire behaviour of a carbon-PEKK composite used for aeronautical applications

Composite materials used for aerospace applications are vulnerable when exposed to high temperatures. Therefore, the development and the using of these materials are strictly framed by aviation regulations where severe fireproof requirements must be accomplished. In the light of this, experimental research is of crucial importance in the understanding of the thermal behaviour of composites materials for aircraft parts, especially when they might be exposed to high-temperature or fire conditions. In this context, thermal degradation of the thermoplastic resin polyether-ketone-ketone (PEKK) with carbon reinforcement is studied. This composite belongs to the polyaryletherketone (PAEK) family, which is known for its high performances. The carbon-PEKK thermal behaviour is evaluated from small scale to medium by scale by means of thermogravimetric analysis, Differential scanning calorimetry, Py-GC-MS and cone calorimeter. The different experiments demonstrate the high thermal performance of the carbon-PEKK composite. Indeed, the latter does not present any decomposition below 500°C, as well as a low amount of volatiles emitted during the resin decomposition. The cone calorimeter experiments confirm the results obtained at small scale and demonstrate that the low yield of volatiles induces a low amount of heat release when exposed to a radiative heat flux. Moreover, the samples present a reduced temperature on the backward face. Finally, these results suggest that the carbon-PEKK might ensure the confinement of a fire as well as a limitation of the fire spread.

Nanocomposites based on polyarylene ether ketones from sol–gel process: Characterizations and prospect applications

The structure and properties of nanocomposites based on amorphous polyarylene ether ketones with different functional side groups (methyl, phthalide, phthalimidine) are investigated. Nanocomposites are prepared by in situ filling of the polymers; metalloalkoxysiloxanes, namely, tris-(methyldiethoxysiloxy)iron, tetrakis-(methyldiethoxysiloxy)zirconium and tetrakis-(methyldiethoxysiloxy)hafnium, were used as precursors for the filler phase. It is demonstrated that the chemical structure and polarity of the matrix macromolecule side groups are the key factors that determine the design of an in situ generated nanofiller (size, density, inhomogeneity or a continuous network structure). The in situ filling of polyarylene ether ketones does not impair their unique thermal properties and promotes an improvement in the tensile stress for the breaking of the nanocomposites that they are based on. The discussed approach for preparing nanocomposites based on thermo-stable polymers is promising for the creation of functional materials with tunable characteristics, such as dielectric properties and their resistance to atomic oxygen.

Optimization of the amount of short glass fibers for superior wear performance of PAEK composites

In this work, the influence of amount (30 and 40 wt.%) of short glass fibers (SGF) in two composites containing synthetic graphite (10 wt.%) and Polyaryl ether ketone (PAEK) (60 wt.% and 50 wt.%) on thermal, mechanical and tribological performance was studied. The theme was to investigate wear-mechanical property correlation. Although the higher amount of SGF led to higher mechanical properties, tribological properties were not in tune to this. Overall, friction coefficient (µ) and specific wear rate (K0) for the composites were in the range 0.04–0.08 and 3–8 × 10−16 m3/Nm respectively and decreased with increase in applied PV values till failure was observed. PVlimit was indicated at 112 and 100 MPa m/s for 30 wt.% and 40 wt.% SGF filled composites respectively. The mechanical properties of the composite with 40 wt.% GF (CGF40) proved superior to a composite with 30 wt.% GF (CGF30).

Role of micro and nano-particles of hBN as a secondary solid lubricant for improving tribo-potential of PAEK composite

Hexagonal boron nitride (hBN), also called as white graphite is known to exhibit excellent combination of thermal, thermo-physical, mechanical and tribological properties as a filler (solid lubricant). Not much reported on its potential as nano-particles. In this study, micro and nanocomposites of hBN were prepared with the combination of polyaryl ether ketone (PAEK) as a matrix (50%), short glass fibers (GF) (30%) as a reinforcement and natural graphite (10%) as a primary solid lubricant (SL) apart from hBN particles (10%) as a secondary SL. The micro-composite (MC) and nano-composite (NC) contained hBN particles in micron size and combination of micron and nano size (7 and 3%) respectively. The NC exhibited enhanced mechanical and tribological performance compared to the MC. Tribological tests were performed on a pin-on-disc tribometer under dry sliding regime to evaluate PVlimit (pressure x velocity) values. Influence of load and sliding speed on the friction coefficient (μ) and specific wear rate (K0) on the composites was investigated. The composites showed PVlimit of 100 MPa m/s along with μ in the range of 0.04–0.08 and K0 in the range of 2.5–7 × 10− 16 m 3/Nm. It was also found that the superior performance of NC was due to more efficient, thin and coherent film transferred on the disc. Moreover, structural and morphological changes were studied with Raman spectroscopy and scanning electron microscopy (SEM). Wear mechanism of the worn surfaces were discussed using XPS (X-ray photoelectron spectroscopy).

Influence of Temperature on Friction and Wear Characteristics of Polyaryletherketones and Their Composites Under Reciprocating Sliding Condition

The tribological behavior of different polyaryletherketones (PAEKs) and their composites was studied under reciprocating sliding conditions at room temperature as well as at elevated temperature (120 °C). The effect of glass, carbon fiber and solid lubricants (PTFE and graphite) filled in PAEK matrix was investigated at different normal loads. It was found that friction and wear characteristics are strongly influenced by the type of PAEK matrix and the material composition. The temperature has a more pronounced influence on the coefficient of friction and specific wear rates of PAEKs and their composites than the normal load. Friction and wear mechanisms are discussed, using scanning electron micrographs of the worn surfaces. A relationship between the average coefficient of friction and specific wear rates of PAEKs and their composites is also reported.

Poly(aryl ether ketone) based individual, binary and ternary nanocomposites for nuclear waste storage: mechanical, rheological and thermal analysis

In this study poly aryl ether ketone (PAEK) based nanocomposites containing multi walled carbon nanotubes, boron carbide and tungsten carbide nanofillers were irradiated with gamma rays of dosage 5000 kGy. These composites were prepared to estimate their potential in nuclear waste storage applications. The tensile properties, non destructive testing, rheological behavior and thermal properties of the composites were evaluated before and after gamma irradiation. The property variation after irradiation was influenced by the cross linking and chain scission of the polymer developed within the nanocomposites. In the tensile property analysis, the tensile modulus and the percentage elongation at break of all the nanocomposites were modified after gamma irradiation. Non destructive testing (NDT) showed all the samples were free from voids and cracks after gamma rays exposure. There was a slight decrease in the complex viscosity of the samples after irradiation indicating the predominance of the chain scission over cross linking. The decrease in melting temperature and the crystallization temperature of PAEK and the nanocomposites after irradiation suggested changes in the conformation of the polymer chains which was validated by the gel permeation chromatography (GPC) analysis. Even though the properties of the virgin PAEK were significantly reduced after gamma irradiation, the percentage reduction in the properties of polymer nanocomposites was not considerable especially with the ones reinforced with tungsten carbide.

Tungsten carbide, boron carbide, and MWCNT reinforced poly(aryl ether ketone) nanocomposites: Morphology and thermomechanical behavior

ABSTRACTThis study involves the development and thermo‐mechanical characterization of the individual, binary, and ternary nanocomposites using radiation resistant fillers like boron carbide (B4C), tungsten carbide (WC), and functionalized multi‐walled carbon nanotubes (F‐MWCNT) in a high performance polymer, namely, poly aryl ether ketone (PAEK). Transmission electron microscopy studies revealed the distribution and dispersion of nanofillers in the matrix. It has been observed that the presence of WC and F‐MWCNT in PAEK matrix significantly enhanced the tensile strength of the composite whereas B4C made it stiff and brittle in nature. The tensile property improvement caused by WC and F‐MWCNT has been correlated with the tensile fracture surface morphology studies. Dynamic mechanical analysis provided insight into the positive effect of nanofillers in delaying the relaxation of polymer chains. The thermogravimetric analysis gave indications on the increase in the thermal stability of the nanocomposites with the increase of nanofillers content. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47032.

POLYARYLENEETHERKETONES OBTAINING WITH REACTION OF NUCLEOPHILIC SUBSTITUTION

The article deals with the study of influence of the synthesis conditions on the molecular weight of polyaryleneetherketones (PAEK), received with nucleophilic substitution reaction of activated aryl halide. The synthesis of PAEK with the nucleophilic substitution reaction carried out as partially hydrolyzed homopolycondensation of phenolates and aromatic dihalides containing a carbonyl group in the molecule and derivatives of polycondensation of aromatic bisphenols with activated aromatic dihalides, and aromatic nitro compounds. The nucleophilic substitution of halogen in aryldihalogens proceeds through formation of Meisenheimer complex, where the negative charge of the electron-electron ring stabilizes the group. The high efficiency of the synthesis of PAEK with nucleophilic substitution reaction is mainly determined with several factors, the main of which are: 1) the structure of the starting monomers; 2) the nature of the solvent; 3) the nature of phenolate; 4) side reactions. For these materials it was revealed that the ratio of nucleophilic and electrophilic reagents has pronounced effect on the molecular weight of the obtained polymer, without affecting the poly dispersion. PAEK synthesis processes are optimized by controlling the replacement of some of the monomers, the temperature and concentration of reactants change. It was shown that the polyarylene ether ketones and copolymers have a high thermal heat resistance, mechanical properties. They show considerable heat resistance in air, capable of forming a transparent film and melts. Thus, data of literature review show that the nucleophilic substitution reaction is promising for PAEK synthesis of various chemical structures and produces polymers having valuable properties.

Release and flammability evaluation of pyrolysis gases from carbon-based composite materials undergoing fire conditions

In the event of fire, composite materials can be exposed to high heat flux leading to a significant release of smoke and toxic fumes that can contribute to the growth of the fire. This can be problematic in the aerospace industry where strict fire regulations are imposed for designated fire zones. Research has therefore been carried out in recent years to estimate the volatile emissions and self-ignition risk during the development phase of composite parts. In the present study, gaseous emissions and lower flammability limits (LFL) were evaluated during the degradation of three carbon-reinforced composites. The thermoplastic polyetherketoneketone (PEKK), belonging to the polyaryletherketone (PAEK) family, which is known for its high-temperature stability, was compared with two thermosetting resins: a classic phenolic resin and a fire improved epoxy. The former is well known and already used as thermal protection whereas the latter could be used as ablative protection for internal thermal insulation. Gaseous emissions were measured using an analytical pyrolyser (heated platinum filament) coupled with a gas chromatograph and a mass spectrometer (Py-GC–MS) for four different temperatures: 360, 450, 590 and 750 °C. From the suspected species given by the pyrolysis experiments, the LFLs were determined by means of a Quantitative Structure-Property Relationship. The classification of the three materials in terms of combustibility (degradation temperature and mass loss) and ignitability (gaseous emissions and lower flammability limit) revealed superior performances of PEKK composites. The benefit of the fire treatment on the carbon-epoxy was demonstrated by a higher value of LFL whereas the carbon-phenolic resin had a lower mass loss even if it presented a lower degradation temperature.

Preparation and properties of novel alternating poly(aryl ether ketone)

Novel alternating poly(aryl ether ketone)s (PAEKs) were prepared from a multiple aromatic difluoroketone monomer, that is, containing six aromatic rings via nucleophilic substitution polycondensation with various bisphenols. Each chain segment of the synthesized poly aryl ether ketone alternating copolymer was regularly separated by bisphenol units, which resulted in improvements in their thermal stability and solubility in common organic solvents. All glass transition temperatures of the alternating PAEKs were above 179°C, and the temperatures at 5% weight loss were above 446°C under nitrogen atmosphere. Wide-angle X-ray diffraction patterns confirmed that the resulting PAEKs were amorphous. PAEKs can form strong, transparent, and flexible films by solution casting, with a tensile strength of 72–79 MPa, Young’s modulus of 1.5–2.0 GPa, and elongation at break of 7–17%.