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Background/purpose: Challenges exist regarding the bonding efficiency of polyaryletherketone (PAEK), a high-performance thermoplastic, attributed to its chemical inertness and hydrophobic surface, hindering effective bonding with resin-matrix cement. This research explored the impact of handheld nonthermal plasma (HNP), under varying operational parameters, on PAEK surface wettability and changes in bonding performance with cement. Materials and methods: Three types of disc-shaped PEAK specimens were prepared, with surface treatments categorized as grinding, airborne-particle abrasion (APB), and HNP. Surface wettability was analyzed using a contact angle analyzer (n = 10). Specimens were bonded with resin cement and subjected to artificial aging tests: distilled water bath (NA), thermocycling, and highly accelerated stress tests (n = 10 for each test). Shear bond strength (SBS) was measured, failure modes were analyzed, and statistical analyses were conducted. Results: The HNP markedly improved PAEK surface wettability, achieving superhydrophilicity (P

Background/purpose: The handheld nonthermal plasma (HNP) treatment may alter the surface properties, bone metabolism, and inflammatory reactions of polyaryletherketone (PAEK) dental implant materials. This study tested whether the HNP treatment might increase the biocompatibility, surface hydrophilicity, surface free energies (SFEs), and the cell adhesion and mineralization capability of PAEK materials. Materials and methods: Disk-shaped samples of titanium (Ti), zirconia (Zr), polyetheretherketone (PEEK [PE]), and polyetherketoneketone (PEKK [PK]) were subjected to HNP treatment and termed as TiPL, ZrPL, PEPL, and PKPL, respectively. Water-surface reactions were examined using a goniometer. MG-63 cells were cultured on all samples to assess the cell viability, cytotoxicity, cell attachment, and mineralization characteristics. The expression of pro-inflammatory cytokines (tumor necrosis factor-alpha and interleukin-6) and key mineralization markers (alkaline phosphatase [ALKP], osteopontin [OPN], and dentin matrix protein 1 [DMP1]) was measured using enzyme-linked immunosorbent assay kits. Results: The HNP-treated samples exhibited significantly enhanced surface hydrophilicities and SFEs compared to the untreated samples. The cell viability remained high across all samples, indicating no cytotoxic effects. The HNP treatment significantly enhanced MG-63 cell adherence and proliferation. Elevated levels of ALKP and OPN were observed for the plasma-treated PEPL and PKPL specimens, while DMP1 levels increased significantly only in the PKPL specimen. Pro-inflammatory cytokine levels were low across all samples, suggesting no inflammatory response. Conclusion: The HNP-treated PAEKs have enhanced the surface hydrophilicity and SFEs as well as superior cell adhesion and mineralization capability, and thus may be good clinical dental implant materials.

The handheld nonthermal plasma (HNP) treatment may alter the surface properties, bone metabolism, and inflammatory reactions of polyaryletherketone (PAEK) dental implant materials. This study tested whether the HNP treatment might increase the biocompatibility, surface hydrophilicity, surface free energies (SFEs), and the cell adhesion and mineralization capability of PAEK materials. Disk-shaped samples of titanium (Ti), zirconia (Zr), polyetheretherketone (PEEK [PE]), and polyetherketoneketone (PEKK [PK]) were subjected to HNP treatment and termed as TiPL, ZrPL, PEPL, and PKPL, respectively. Water-surface reactions were examined using a goniometer. MG-63 cells were cultured on all samples to assess the cell viability, cytotoxicity, cell attachment, and mineralization characteristics. The expression of pro-inflammatory cytokines (tumor necrosis factor-alpha and interleukin-6) and key mineralization markers (alkaline phosphatase [ALKP], osteopontin [OPN], and dentin matrix protein 1 [DMP1]) was measured using enzyme-linked immunosorbent assay kits. The HNP-treated samples exhibited significantly enhanced surface hydrophilicities and SFEs compared to the untreated samples. The cell viability remained high across all samples, indicating no cytotoxic effects. The HNP treatment significantly enhanced MG-63 cell adherence and proliferation. Elevated levels of ALKP and OPN were observed for the plasma-treated PEPL and PKPL specimens, while DMP1 levels increased significantly only in the PKPL specimen. Pro-inflammatory cytokine levels were low across all samples, suggesting no inflammatory response. The HNP-treated PAEKs have enhanced the surface hydrophilicity and SFEs as well as superior cell adhesion and mineralization capability, and thus may be good clinical dental implant materials. [ABSTRACT FROM AUTHOR]

Challenges exist regarding the bonding efficiency of polyaryletherketone (PAEK), a high-performance thermoplastic, attributed to its chemical inertness and hydrophobic surface, hindering effective bonding with resin-matrix cement. This research explored the impact of handheld nonthermal plasma (HNP), under varying operational parameters, on PAEK surface wettability and changes in bonding performance with cement. Three types of disc-shaped PEAK specimens were prepared, with surface treatments categorized as grinding, airborne-particle abrasion (APB), and HNP. Surface wettability was analyzed using a contact angle analyzer (n = 10). Specimens were bonded with resin cement and subjected to artificial aging tests: distilled water bath (NA), thermocycling, and highly accelerated stress tests (n = 10 for each test). Shear bond strength (SBS) was measured, failure modes were analyzed, and statistical analyses were conducted. The HNP markedly improved PAEK surface wettability, achieving superhydrophilicity (P < 0.05). This effect intensified with extended operation times (30 or 60 s) and reduced elapsed times (<30 s). HNP-treated PAEK exhibited higher SBS than APB (P < 0.05) and maintained bonding durability after artificial aging, particularly in ketone-enriched variants. Failure analysis revealed predominantly adhesive failure under APB–NA treatment, mixture failures under HNP–NA treatment and postaging, but no cohesive failure. The HNP device benefits dental settings by transforming the PAEK surface into superhydrophilic properties, thereby improving PAEK–cement bonding. It significantly enhances bond durability within 30 s of operation and after a 30 s elapsed period. It is noteworthy that ketone-enriched PAEK demonstrates markedly improved bonding performance. [ABSTRACT FROM AUTHOR]

Polyaryletherketone (PAEK) thermoplastic composite materials have received increasing attention for the manufacturing of composite structures. One manufacturing process of great interest for PAEK composite structures is automated fiber placement, which can increase the throughput of complex part fabrication and reduce the use of autoclaves for assembly of composite parts. Understanding the thermal effects of the material allows the control and adjustment of manufacturing variables to assure the integrity of the composite structure. PAEK resins and carbon fiber reinforced composites have been analyzed using differential scanning calorimetry to study crystallization kinetics. Isothermal and non‐isothermal tests were conducted, and the time‐dependent crystallization kinetics were modeled using the Velisaris and Seferis model for isothermal processes and the Gaussian process regression method for non‐isothermal processes. The results show the influence of the thermal conditions and the chemical structures considering the ketone content, and the effects of the presence of the carbon fibers on crystallization kinetics. The models utilized describe with high accuracy the time‐dependent crystallization kinetics of PAEK composite materials. An artificial neural network application was also implemented using the non‐isothermal PAEK composite models for further prediction of relative volume crystallinity and crystallization rate. Highlights: Polyaryletherketone (PAEK) materials crystallize differently depending on the crystallization conditions.Carbon fibers influence the crystallization response in PAEK polymers.Machine learning was used to characterize crystallization kinetics.Activation energies were obtained for different thermal treatments.Artificial neural network tool was developed for PAEK composites in non‐isothermal regimes. [ABSTRACT FROM AUTHOR]

ABSTRACTAchieving good dispersion of graphene (GNP), in polyetheretherketone (PEEK), is challenging due to the high melt viscosity, solvent resistance and processing temperature of PEEK. In addition, certain manufacturing processes tend to enhance the anisotropy due to GNP orientation within the structure. This study investigated the fabrication of nanocomposite parts through hot compression moulding (C-MOULD) and powder bed fusion (PBF) processes, using powder with GNPs fused to the surface of polymeric particles, through a process called mechanofusion. The method applies mechanical forces of compression, shear and impact to generate a mechanical bond between materials, in this case, O2 functionalised GNP and a developmental polyaryletherketones (PAEK) grade powder. The novelty of this work is in the combination of processes used for manufacturing (material preparation and actual manufacturing processes), which are scalable and efficient in comparison with existing methods (such as solvent mixing or melt-compounding). The mechanofusion GNP-PAEK composite powders were successfully printed for the first time using the EOS P800 system with notable improvements in electrical and mechanical properties. This study highlights that the mechanofusion process could be used as an efficient process for making multifunctional nanocomposite materials and this can be combined with additive manufacturing (AM) processes to produce complex components.

In this study, a highly effective cationic polymer, Poly (diallyldimethylammonium chloride) (PDDA), was used to bond Titanium Carbide (TiC) nano-particles (NPs) non-covalently with matrix polyaryletherketone (PAEK). Functionalization of PDDA to TiC NPs was confirmed using Fourier-transform infrared spectroscopy (FT-IR), Zeta potential, and Field Emission Scanning Electron Microscopy (FE-SEM). Both TiC NPs (3 wt%) (untreated and PDDA-treated) were added to PAEK, as a filler for reinforcement and elevating friction. The addition of TiC NPs (untreated and treated) in the PAEK led to an improvement in selected performance properties such as thermal stability (by 11 and 13 °C), surface free energy (17 and 29%), and lap shear strength (LSS) (116 and 161%) respectively. Plastic deformation, cup formaion and micro-striation formation were the major failure mechanisms. PDDA treatment to TiC NPs resulted in better and more uniform deagglomeration in the PAEK matrix, strengthened particle-matrix interface, higher surface energy, and hence more adhesion with the adherend. The improved strengthening of both the interfaces (NPs with the matrix and nanocomposite with the metallic adherend) led to an enhanced performance by the treated NPs.

Electrochemical oxidation of carbon fiber (CF) is used to enhance the interfacial adhesion of CF-reinforced polyaryletherketone (CF/PAEK) composites. The effect of current intensity parameter on surface structure of CF and interfacial properties of the corresponding thermoplastic composites are deeply investigated. The results show that the current intensity in the range of 80 A–300 A does not lead to a decrease in the mechanical property of CFs. When the current intensity is 200 A, CF/PAEK composites have the highest interfacial performance, which is mainly due to the improvement of CF surface roughness, wettability, and oxygen content. In addition, the degree of graphitization of CF surface is also a crucial factor affecting the interfacial properties of CF/PAEK. The higher the content of carboxyl groups, the more disordered the structures exist on the CF surface, which are not conducive to the strong adhesion of CF to PAEK resin. Therefore, balancing the wettability and graphitization degree of the CF surface is the key to enhancing the CF/PAEK interfacial properties by electrochemical treatment techniques. [ABSTRACT FROM AUTHOR]

The present paper reports the analyses of results obtained from experiments carried out to explore the challenge of homogeneous, uniform, and deagglomerated dispersion of ultra-heavy nanoparticles (NPs) in the high-performance polyaryletherketone (PAEK) matrix. An equal and fixed amount of (0.5 vol. %) NPs of silicon carbide (SiC), zirconium carbide (ZrC), and tungsten carbide (WC) were dispersed in a PAEK matrix and compression molded to develop three different nanocomposites. Simultaneously, nano-adhesives of the same composition were also developed to join the stainless steel adherends. The composites and adhesives were characterized for their physical, thermal, thermo-mechanical, thermal conductivity (TC), and lap shear strength (LSS) behavior. It was observed that SiC NPs performed significantly better than ZrC and WC NCs in all performance properties (LSS: 154%, TC: 263%, tensile strength: 21%). Thermal conductivity (TC) and tensile properties were validated using various predictive models, such as the rule of mixture parallel model, the Chiew and Glandt model, and the Lewis model. Scanning electron micrographs were used for the morphological analysis of LSS samples to detect macro- and micro-failure. Micrographs showed evidence of micro-striation and plastic deformation as a micromodel, as well as mixed failure, i.e., adhesive–cohesive as a macro-failure mode. [ABSTRACT FROM AUTHOR]

Carbon molecular sieve (CMS) membranes demonstrate promising economic and environmental advantages in gas separation applications. In this work, we synthesized a novel polymer precursor of PEK-N and utilized it to fabricate a series of PEK-N derived CMS membranes. With varying carbonization temperature and time, the pore structures and gas separation performance were finely tuned. The gas separation properties of membranes with different carbonization temperature were comprehensively evaluated. In particular, by carbonizing the sample at 650 °C for 1 h, PEK-N derived CMS membranes (CMS-650-1) achieved the highest CO 2 permeability around 2176 Barrer, and selectivities of 48.2 for CO 2 /N 2 and 57.8 for CO 2 /CH 4 in their gas mixtures. Our study suggests that the use of rationally designed polymers has the potential to bring about high gas separation performance for polymer-derived carbon molecular sieve membranes. This study explores the use of a novel polymer of polyaryletherketone bearing tertiary amine group (PEK-N) for preparing carbon molecular sieve membranes through control of carbonization temperature and time. The optimized CMS membrane (CMS-650-1) exhibited a CO 2 permeability around 2176 Barrer, and CO 2 /N 2 and CO 2 /CH 4 gas selectivities of 48.2 and 57.8, respectively. [Display omitted] • Polyaryletherketone bearing tertiary amine group polymer was synthesized. • CMS membranes were fabricated using PEK-N polymer. • The structural features of CMS membranes could be tuned by adjusting the carbonization temperature and time. • The CMS membrane exhibited high separation performance for CO 2 /N 2 and CO 2 /CH 4. [ABSTRACT FROM AUTHOR]

High‐performance thermoplastic composites are gaining attention as potential replacement for thermoset composites in high‐end structural applications owing to their superior fracture toughness and recyclability. In this study, polyaryletherketone (PAEK) and carbon fabric (CF) reinforced PAEK are compared with epoxy and epoxy‐CF composites. PAEK‐CF composites are prepared by film stacking method followed by compression molding while hand lay‐up technique was used for epoxy‐CF composites. PAEK and PAEK‐CF composites possess superior tensile properties, flexural strength and fracture toughness compared to those prepared from epoxy. The incorporation of CF improved the wear resistance in both PAEK and epoxy and PAEK‐CF exhibited the lowest wear rate. The investigation of interlaminar shear strength of the composites was conducted and the highest value observed for PAEK‐CF composite. Wear and fracture surface analysis suggested ductile failure for PAEK and PAEK‐CF composites and brittle failure in epoxy composites, as indicated by interfacial bonding/debonding and fiber pullout, at the fracture surface. Cryo‐thermal cycling effects on the tensile properties, fracture toughness and fracture surface morphology of the composites are studied. The failure behavior obtained from experimental studies was corroborated with finite element method‐based simulation models of fracture toughness response in single edge notch bend test using Abaqus/Explicit. [ABSTRACT FROM AUTHOR]

Powder spreadability in the powder bed fusion process is normally visually assessed by the machine operator through repeat trials at room temperature or elevated temperatures. Some studies used powder rheology results as an indicator of the powder spreadability. This study presents a novel method of image-based analysis for the assessment of polymer spreading quality for powder bed fusion and demonstrates that the subjective assessment of the machine operator can be replaced by quantitative and measurable data. Twenty-four developmental grade PolyArylEtherKetone powders were tested. Images of the powder bed surface were analysed in MATLAB and the relationships with the powder rheology established through statistical analysis. The two methods for calculating surface deviations from variations in the greyscale images showed to be sensitive to the recoater travel and presented a strong correlation with the Normalised Aeration Sensitivity (NAS), a powder rheology parameter identified in a previous study as the most significant parameter able to categorise powder flow and spreadability based on a yes/no response. [Display omitted] • PolyArylEtherKetone powders are assessed for polymer Powder Bed Fusion. • Bespoke powder spreading apparatus enables image capture during spreading. • Variable flow properties create defective powder surfaces. • Two methods created in MATLAB to quantify the surface quality. • Surface quality data correlates with powder rheometer key values. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) is a green, efficient and energy-saving new separation technology. However, it is exigent to membrane materials with both good soluble processability and solvent resistance, as well as methods for preparing composite membranes that combine high accuracy and stability. In this work, a novel polyaryletherketone containing phenylamine structure (PEK-PA) was prepared and used to fabricate a novel solvent resistant composite membrane via strategies of chemical crosslinking and polymer filling into the surface pores of the membrane. The crosslinking between PEK-PA and trimesoyl chloride improves the solvent resistance of the membrane and the strategy of polyamide filling improves the separation accuracy of the membrane. The prepared OSN membranes exhibit exceptional separation accuracy, with a molecular weight cut-off within the range of 214 g mol−1 to 383 g mol−1. More importantly, the prepared membranes exhibit higher stability than the thin-film-composite membranes prepared by interfacial polymerization, which was demonstrated by a designed reverse pressure experiment. The prepared membranes can be continuously operated in DMF for 60 h, thereby demonstrating their excellent stability even for harsh polar aprotic solvents. Therefore, this work presents a novel solvent resistant membrane material with potential applications for OSN. Schematic diagram of the preparation process of F-PEK-PA-MPD membranes. [Display omitted] • A novel crosslinkable polyaryletherketone containing phenylamine was prepared. • Polymer filling strategy improves separation accuracy and stability simultaneously. • The prepared composite membranes can withstand the reverse pressure of 1.6 Mpa. • The prepared membranes can be continuously operated in DMF. [ABSTRACT FROM AUTHOR]

A heat‐resistant soluble hyperbranched polyaryl ether ketone (HPAEK) is synthesized as the main resin of sizing agent and coated on the surface of carbon fiber (CF) with active group. As a result, the monofilament tensile strength of CF is increased by 12.00% and due to the improved fiber surface wettability and interface compatibility between CF and polyether ether ketone (PEEK), a 68.29% increase of interlaminar shear strength is achieved. [ABSTRACT FROM AUTHOR]

Purpose: To compare retentive forces of removable partial denture clasps traditionally fabricated with cobalt‐chromium (CoCr) material and two computer‐aided design and computer‐aided manufactured (CAD/CAM) thermoplastic polymers. Materials and Methods: Forty‐eight clasp assemblies (16 CoCr, 16 polyetheretherketone (PEEK) and 16 polyetherketoneketone (PEKK) thermoplastic polymer) were fabricated for 48 mandibular tooth analogs. Individual clasps were inserted and removed on the tooth analogs utilizing a chewing simulator for 15,000 cycles to simulate 10 years of use. Retentive forces were measured utilizing a mechanical load tester at baseline and intervals of 1500 cycles. Data were analyzed with one‐way Analysis of Variance, Tukey post‐hoc, and paired T tests. Results: Mean retentive forces between all groups were significantly different (p < 0.001). Retentive forces of CoCr clasps were significantly higher than both polymers (p < 0.001). The mean retentive forces for PEEK were not significantly different from PEKK (p = 0.23). A significant increase in retentive forces was observed for all three clasps after the first period of cycling, followed by continual decrease for the remaining cycles. At the endpoint of 15,000 cycles, no clasp assemblies showed lower retentive forces than at initial baseline. Conclusion: Thermoplastic polymer clasps demonstrated lower retentive forces compared to CoCr clasps. All three groups displayed a similar pattern of initial increase, followed by a gradual decrease, of retentive force. Despite this observation, the clasps maintained similar or higher retentive forces than measured at baseline. This resistance to fatigue and ability to fabricate with CAD/CAM technologies provides support for clinical use of these high‐performance polymer (HPP) materials. [ABSTRACT FROM AUTHOR]

The present paper reports the analyses of results obtained from experiments carried out to explore the challenge of homogeneous, uniform, and deagglomerated dispersion of ultra-heavy nanoparticles (NPs) in the high-performance polyaryletherketone (PAEK) matrix. An equal and fixed amount of (0.5 vol. %) NPs of silicon carbide (SiC), zirconium carbide (ZrC), and tungsten carbide (WC) were dispersed in a PAEK matrix and compression molded to develop three different nanocomposites. Simultaneously, nano-adhesives of the same composition were also developed to join the stainless steel adherends. The composites and adhesives were characterized for their physical, thermal, thermo-mechanical, thermal conductivity (TC), and lap shear strength (LSS) behavior. It was observed that SiC NPs performed significantly better than ZrC and WC NCs in all performance properties (LSS: 154%, TC: 263%, tensile strength: 21%). Thermal conductivity (TC) and tensile properties were validated using various predictive models, such as the rule of mixture parallel model, the Chiew and Glandt model, and the Lewis model. Scanning electron micrographs were used for the morphological analysis of LSS samples to detect macro- and micro-failure. Micrographs showed evidence of micro-striation and plastic deformation as a micromodel, as well as mixed failure, i.e., adhesive–cohesive as a macro-failure mode.

Amongst additive manufacturing processes, fused filament fabrication (FFF) is one of the most affordable and cost‐efficient technologies that can produce complex shaped components with an increasing number of printable polymers such as the polyaryletherketone family, polyetherimide and polyphenylene sulfide. Despite the gain in popularity, there is a lack of standardisation in specimen preparation and mechanical testing of FFF samples. This study investigates the effect of different methods of printing vertical tensile specimens on the mechanical properties when the material and the printing parameters are fixed. A slow crystallising polyetherketoneketone grade was selected as the printing material to exclude the effect of crystallisation on the interlayer bonding strength, leaving the temperature‐dependent amorphous molecular diffusion across the layers as the governing mechanism. Vertical tensile specimens made by four printing methods – individually printed, machined and connected (based on ISO 527‐2‐1A and ISO 527‐2‐1BA) – were assessed. Individually printed vertical specimens were found to have the highest mean tensile strength, owing to the high level of diffusion induced by the very short layer time. The strengths of specimens printed via the other three methods are less sensitive to the effect of layer time, due to the lower rate of change during cooling and its relationship with the local temperature at the interlayer surface. This study highlights the importance of the disclosure of FFF printing methods along with any reported mechanical data. © 2021 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

Fusion bonding theory is applied to the additive manufacturing process to predict the strength developed across the interface between the deposited layers in material extrusion based large‐scale additive manufacturing. Relaxation times were determined through rheology investigations of the neat polymers and were extrapolated across the entire process temperature range to estimate the required welding times for optimal bond formation. For the calculation of bond formation during cooling from the melt, the semicrystalline polyaryletherketone is considered amorphous until the onset of crystallization which is determined by recreating the process thermal history in DSC measurements. A significant improvement in bond development during additive manufacturing is achieved through the use of specifically designed polymers with slower crystallization kinetics. Both in small‐scale additive manufacturing, achieving full bonding, and in large‐scale additive manufacturing, they achieve significantly higher interlaminar strength than the reference material, validated by three‐point bending. A very good match between the estimated degree of bonding and the tested strength of upright printed specimens in three‐point bending was found. While the fusion bonding model calculates a degree of bonding of 42.07%, mechanical testing showed 42.54% of the bulk flexural strength. The study outlines a procedure to evaluate materials for additive manufacturing by material extrusion based on small material samples to shorten and improve the process development. © 2020 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Industrial Chemistry [ABSTRACT FROM AUTHOR]

Polyaryletherketone (PAEK)/CaCu 3 Ti 4 O 12 (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 (n CCTO) 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 n CCTO. Melting temperature of pure PAEK was about 372 °C, which did not change significantly with the addition of n CCTO. 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 n CCTO, 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. [ABSTRACT FROM AUTHOR]

Organic solvent nanofiltration (OSN) is a new type of organic fluid separation technology that can greatly reduce energy consumption compared with traditional distillation techniques. However, the development and application of OSN are restricted by the high manufacturing cost of solvent resistant membranes, including expensive materials and complex post-treatment process. In this paper, a low-cost polyaryletherketone bearing amino group synthesized from industrial raw material phenolphthalein was proposed, and then the crosslinked polyaryletherketone membrane with remarkable stability in polar aprotic solvent was prepared by green, mild and simple crosslinking method. The separation accuracy of the membrane can be easily adjusted from ultrafiltration to nanofiltration by altering the composition of the cast solution. In addition, the prepared membrane can be operated in DMF for 120 h, which indicated the excellent stability of the membrane, even for hash polar aprotic solvents. Therefore, this work demonstrates a novel low-cost solvent resistant membrane material that is promising for OSN applications. Schematic diagram of the preparation process of crosslinked PEK-NH 2 membranes. [Display omitted] • A novel low-cost polymer membrane material with good comprehensive performance. • Crosslinking occurs in aqueous solutions, which is a green, mild, and simple process. • The separation accuracy of the membrane can be easily adjusted from ultrafiltration to nanofiltration. • The crosslinked membranes exhibited excellent stability in common organic solvents including DMF. [ABSTRACT FROM AUTHOR]

Polyaryletherketone (PAEK) polymers are unique thermoplastics certified for aerospace and biomedical applications, demonstrating exceptional thermo-mechanical characteristics and superior chemical resistance. They are adaptable to material extrusion (ME) and laser powder bed fusion (L-PBF) additive manufacturing systems. While various PAEK grades for additive manufacturing (AM) exist, their printing suitability, especially inter-layer strength, is not well-understood. Adding small amounts of short carbon fibers to PAEKs enhances their stiffness and service temperature but modifies their processing, structure, and properties. This study examines the effects of the AM method (L-PBF and ME) and carbon fiber addition on the structure, mechanical properties, and crystallinity of three different PAEK polymers. We characterize and correlate tensile properties, fracture modes, degree of crystallinity, fiber length and orientations, and porosity of the samples. Our findings aim to refine AM processes and feedstock materials for semi-crystalline polymers and their composites, offering insights for designing robust, economical AM parts. [ABSTRACT FROM AUTHOR]

In this study, the Taguchi method was utilized to optimize fused filament fabrication (FFF) additive manufacturing with the goal of maximizing the flexural strength of 3D printed polyaryletherketone specimens. We analyzed 3D printed (3DP) carbon fiber reinforced poly-etherketoneketone (CFR PEKK), 3D printed and pressed (3DP + P) CFR PEKK, and injection molded medical grade polyetheretherketone (PEEK) as a control. Fracture surfaces were analyzed via scanning electron microscopy (SEM). The parameters that were varied in the optimization included nozzle diameter, layer height, print speed, raster angle, and nozzle temperature. We analyzed the flexural strength and flexural modulus determined from 3-point bending (ASTM D790). Using Taguchi optimization, the signal to noise ratio (SNR) was calculated to determine the relationship between the input parameters and flexural strength and to determine optimal print settings. Results were confirmed with analysis of variance (ANOVA). The raster angle and layer height were determined to have the greatest impact on the flexural strength of specimens printed in the FFF process for 3DP CFR PEKK. The optimized printing parameters were found to be 0/90 Raster Angle, 0.25 mm layer height, 0.8 mm Nozzle Diameter, 375 °C nozzle temperature, and 1100 mm/min print speed. The optimized 3DP CFR PEKK test samples had a flexural strength of 111.3 ± 5.3 MPa and a flexural modulus of 3.5 GPa. 3DP + P CFR PEKK samples had a flexural strength of 257.2 ± 17.8 MPa and a flexural modulus of 8.2 GPa. Statistical comparisons between means demonstrated that pressing significantly improves both flexural strength and flexural modulus of 3DP CFR PEKK. The results of this study support the hypothesis that post consolidation of 3DP specimens improves mechanical properties. Post-processing composites via pressing may allow greater design freedom within the 3DP process while improving mechanical properties. [Display omitted] [ABSTRACT FROM AUTHOR]

Sulfonated fluorenyl-containing polyaryletherketones (SFPAEKs) were synthesized through a postsulfonation approach under a mild reaction condition. The composite proton exchange membranes based on SFPAEKs and various amounts of the modified nanocrystalline cellulose (NCC) were prepared by solution casting method. The existence of the multiple hydroxyl and sulfonic acid groups on the chemically modified nanocrystalline cellulose was supposed to benefit the formation of hydrogen-bond network and proton-conducting channels, which would improve the proton conducting ability of the composite membranes. Furthermore, the properties, such as mechanical properties, thermal stability, water uptake, swelling ratio and so on, were thoroughly investigated. In comparison to the pristine SFPAEK, the composite membranes containing a “performance enhanced” NCC component presented the higher proton conductivity and better mechanical properties. It was found that the proton conductivity of the composite membrane with 4 wt% of NCC could reach 0.234 S cm − 1 at 100 °C, and this value was higher than that of most of the reported membranes. The results showed that the modified nanocrystalline cellulose reinforced SFPAEK composite membrane would be promising for the application as middle-temperature proton exchange membranes in fuel cells. [ABSTRACT FROM AUTHOR]

Advanced engineering polymers of the polyaryletherketone (PAEK) family with carbon fibre reinforcement are finding application in engineering systems as tribological bearing surfaces under severe operating conditions that cyclically move the polymer into and beyond the glass transition temperature region. To support such an application, the friction in high-speed and low-load PAEK-steel sliding contacts was investigated both unlubricated and lubricated with a trinonyl trimellitate ester, a base fluid for high temperature industrial lubricants. Four polymers in the PAEK family, PEEK, PEK, PEKEKK and PEKK, with 30 wt% of carbon fibre whiskers were tested against an AISI 4140 steel disc. When unlubricated, low friction depended upon the formation of a PAEK transfer film on the steel disc and when this became unstable in the glass transition region the friction increased to much higher levels with associated polymer surface damage. Frictional heating due to the high sliding speed dominated the differences in glass transition behaviour between the four PAEKs. When lubricated, the lubricant film controlled friction and there was no significant effect of the glass transition of any of the PAEKs. The irreversible nature of the glass transition in PAEKs in such tribological applications, due to high surface damage at high temperature, means that it is essential to ensure effective lubrication in both fluid film and boundary lubrication. [ABSTRACT FROM AUTHOR]

In a study of unique scale, twenty-four milled Polyaryletherketone (PAEK) polymer powders produced during the development of new grades for Powder Bed Fusion (PBF) were tested using a universal powder rheometer and particle size and shape analyser. Multivariate correlation was used to identify the linear relationships between bulk and dynamic properties and particle size. The flow energy, which measures the energy required to displace powder when in a loosely packed state, was found to have very strong relationships with both the powder density and its compressibility, and both the density and compressibility share a very strong relationship with each other. Partition modelling determined that normalised aeration sensitivity (NAS) was the key indicator when predicting powder spreading. The study highlights the importance for complete and pertinent datasets to allow the development of accurate correlations and the need to capture the PBF spreading performance when developing materials for additive manufacturing. [Display omitted] • Bulk and dynamic flow properties are captured with a Universal Powder Rheometer. • Multivariate Correlation interprets linear relationships between properties. • Key relationships between PSD, Circularity and Powder Rheology are identified. • Normalised Aeration Sensitivity used to predict spreading. [ABSTRACT FROM AUTHOR]

Thermal, mechanical and tribological properties of a new ceramic-polymer nanocomposite in which polyaryletherketone (PAEK) polymer was reinforced with titanium silicon carbide (Ti3SiC2), a ceramic nanolaminate belonging to the MAX phase family (M is an early transition metal, A represents group IIIA or IVA element and X is either carbon and/or nitrogen) are reported for the first time. PAEK-Ti3SiC2 nanocomposites with varying volume fractions of Ti3SiC2 were processed by hot pressing. The effect of Ti3SiC2 on the thermal expansion, bulk hardness, mechanical strength, wear and friction properties was systematically analyzed and the results are discussed. The study confirms that the Ti3SiC2 controlled the high thermal expansion property of PAEK polymer. In addition to that, it enhanced the wear resistance and mechanical strength of PAEK without affecting its inherent low-friction characteristics. [ABSTRACT FROM AUTHOR]

Polyetheretherketone (PEEK) as a popular orthopaedic implant is usually fabricated into a hierarchically porous structure for improving osteogenic activity. However, the applications are limited due to the excessively high processing temperature and uncontrollably tedious modification routes. Here, an amorphous polyaryletherketone with carboxyl groups (PAEK-COOH) is synthesized and fabricated to the hierarchically controllable porous scaffolds via a low-temperature 3D-printing process. The prepared PAEK-COOH scaffolds present controllable porous structures ranging from nano- to micro-scale, and their mechanical strengths are comparable to that of trabecular bone. More importantly, the in vitro experiments show that the nanoporous surface is conducive to promoting cellular adhesion, and carboxyl groups can induce hydroxyapatite mineralization via electrostatic interaction. The in vivo experiments demonstrate that the PAEK-COOH scaffolds offer much better osseointegration without additional active ingredients, compared to that of PEEK. Therefore, this work will not only develop a promising candidate for bone tissue engineering, but provide a viable method to design PAEK biomaterials., (© 2022 Wiley-VCH GmbH.)

Abstract: Europium (Eu3+) and terbium (Tb3+) ions coordinated with 1,10-phenantroline (Phen), N,N-dimethylformamide (DMF) and carboxyl-containing polyaryletherketone (PEK) represent new luminescent materials (, x =0, 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1). The results of FTIR, elemental analysis and XRD confirm that the coordination reaction indeed occurs and the rare earth ions are homogeneously dispersed in the PEK matrix. The polyarylethertone rare earth complexes exhibit high glass transition temperature and good thermal stability because of their wholly aromatic structures. The luminescence measurements indicate that the relative emission intensities of Tb3+ to Eu3+ ions depend on their ratio in the system, and the color of under UV excitation can be tuned by changing the x value. The materials thus prepared show promising potential in the full color large area display field. [Copyright &y& Elsevier]

A series of novel dysprosium coordination polymers were synthesized using new high-T carboxyl-containing polyaryletherketones (PEKs) as macromolecular ligands and a small molecule, 1,10-phenanthroline, as co-ligand. The FTIR, WAXD, and UV-Vis results indicated that the dysprosium ions were coordinated simultaneously with carboxyl group of PEKs and 1,10-phenanthroline, and homogeneously distributed along the polymer backbone. These obtained dysprosium coordination polymers showed excellent film-formation properties. Moreover, all the dysprosium coordination polymers could exhibit the intense characteristic emission of dysprosium ions under UV excitation. Meanwhile, the emission intensity increased with increasing dysprosium ion content, and no obvious fluorescence quenching happened at the Dy ion content up to 10.71 wt%, which was attributed to the very rigid structure of PEK and synergistic coordination effect of PEK and 1,10-phenanthroline. Copyright © 2009 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: The birefringences, optical losses, refractive indices and their temperature dependency over a range of 30–90 °C for the films of carboxyl-containing polyaryletherketones with systematically varied alkyl substituents were investigated in detail. The results showed that the optical losses at 1310 nm were mainly affected by the content of Chereas that at 1550 nm were more related to the presence of Ooreover, two methyls and two bulky isopropyls on the phenylene rings led to the distorted polymer chain, which significantly reduced the chain packing density and disturbed the alignment of polymer chains along the substrate surface, and consequently resulted into the polymer films low refractive indices and birefringences. Furthermore, after conversion of carboxylic group to acyl chloride group, using rigid rod-like hydroquione and twisted phenolphthalein as bisphenol crosslinkers, respectively, the transparent smooth polymer films with three-dimensional network structures were readily obtained at the curing temperature below 200 °C without needing any additional catalyst. The cured polymers exhibited excellent resistance to organic solvents and good thermal stability as well as low birefringence of 0.0019 and greatly decreased optical loss at 1550 nm by about 78%. [Copyright &y& Elsevier]

Abstract: The fluorescence properties of a series of rare earth (Re3+ =Eu3+, Tb3+) polymeric complexes (PEK-Re3+-HLs) using three high-T g novel carboxyl-containing polyaryletherketones (PEK) as macromolecular ligands and small molecules (HL) such as 1,10-phenanthroline (Phen), dibenzoylmethane (DBM) and 8-hydroxyquinoline (HQ) as co-ligands were investigated by means of fluorescence excitation and emission spectroscopy as well as fluorescence lifetime measurement methods. Among them, PEK-1-Re3+-Phens, in which the Re3+ ions were coordinated simultaneously with Phen and PEK-1 containing both carboxyl and bulky isopropyl groups on the polymer backbone, exhibited strong fluorescence intensities, long lifetimes, and good film-formation properties. The smooth films of PEK-1-Eu3+-Phen and PEK-1-Tb3+-Phen, cast from their DMF solutions, could emit bright red and green light under the UV lamp of 365nm, respectively, which characteristics are of great significance for their potential applications in the large area display material fields. The excellent fluorescence properties of complexes in this study were attributed to the synergistic effects of PEK-1 ligand and Phen co-ligand. Especially, the rigid twisted structure and the bulky isopropyl substituents on PEK-1 backbone forced the coordinated rare earth ion moieties apart, and thus the probability of non-radiative decay rate of Re3+ ions at the excited levels were decreased to a large extent. [Copyright &y& Elsevier]