Polyetheretherketone Polymer Research Articles

Thermo-electric Characterization of Hydroxyapatite/ Multi-walled Carbon Nanotube Reinforced Polyetheretherketone Polymer Composites

Thermo-electric Characterization of Hydroxyapatite/ Multi-walled Carbon Nanotube Reinforced Polyetheretherketone Polymer Composites

In vitro assessment of corrosion, antibacterial properties, and degradation behavior of zirconia-coated polyetheretherketone (PEEK)

The medical industry often uses ceramic and polymeric coatings to safeguard metal substrates. However, more investigation is required to explore the implementation of ceramic coatings on polymer substrates and to determine their degradation and in vitro characteristics. This work involves applying zirconia coating onto the 3D-printed PEEK polymer substrate using the RF magnetron sputtering technique. With varying layer thickness and printing speed parameters, PEEK samples (S1, S2, S3, and S4) were 3D printed and coated with zirconia. The coated and uncoated samples were immersed in Fusayama artificial saliva solution for 30 days. Following immersion in artificial saliva, this study examined the corrosion of 3D-printed PEEK samples with and without coatings. Elemental mapping, field emission scanning electron microscopy, and X-ray photoelectron spectroscopy were employed to evaluate sample morphology and estimate the binding energy of possible compounds generated in the artificial saliva solution. In vitro assessments such as antibacterial studies were performed against E. coli and S. aureus, and cytotoxic analysis was performed using Human Wharton’s jelly-derived mesenchymal stem cells (WJ-MSCs) to determine cell proliferation. The results indicated that sample S3, printed with 0.15 mm layer thickness and 20 mm/s print speed coated with zirconia showed a better degradation rate of 9.01% whereas the other three samples S1, S2, and S4 coated with zirconia showed deterioration rates of 36.4%, 33% and 16% respectively. Sample S3 showed a better antibacterial activity as biofilm formation was absent and also showed cell viability of about 79% and hence can be considered as a viable option for dental applications.

Mechanical and tribological assessment of PEEK and PEEK based polymer composites for artificial hip joints

Abstract Human hip failure remains a significant issue, and constructing artificial joints is imperative for affected individuals. This study examined the mechanical and wear behavior of polyether ether ketone (PEEK) polymers, including bare PEEK (BP), HA (Hydroxyapatite)-infused PEEK (HA-PEEK), and GO (Graphene oxide)-infused HA-PEEK (GO-HA-PEEK). The samples were prepared using compression molding, and wear characteristics were evaluated using a linear reciprocating tribo-tester against a stainless-steel counterface under a load 50 N, frequency 5 Hz, stroke length 20 mm, and time 30 min. The 10 % w/w HA inclusions slightly elevate the PEEK’s tensile strength from 29.85 ± 1.11 MPa (BP) to 34.23 ± 1.09 MPa, and the 0.5 % w/w GO with 10 % w/w HA encapsulations have significantly improved tensile properties (65.10 ± 1.12 MPa), which is 2.2 fold higher than the BP. However, the attained impact properties fall below the satisfactory level. Coefficient of friction and wear rate are significantly reduced. The wear rate reduced from 3.39 × 10−6 mm3 N−1 m−1 (BP) to 2.54 × 10−6 mm3 N−1 m−1 on HA-PEEK, and more than two times reduction (1.69 × 10−6 mm3 N−1 m−1) with 0.5 % w/w GO incorporating HA-PEEK. The results show that the reinforcements significantly reduced wear and improved the mechanical strength of PEEK polymers. Unlike BP and HA with lowered impact resistance, GO integrated HA-PEEK exhibited outstanding mechanical and wear performance. Therefore, HA and GO-infused PEEKs are suitable alternatives for hip repair applications.

Development of ANN model for predicting mechanical properties of 3D printed PEEK polymer using FDM and optimization of process parameters for better mechanical properties

Additive manufacturing (AM) has evolved from a proven technology to a rapid prototyping tool with great potential. This technology is widely used in many industries such as automotive, aerospace, and medical; fused deposition modeling (FDM) is a popular 3D printing technique for producing PEEK (polyether ether ketone) parts, including implant prosthetic teeth. In this study, artificial neural network (ANN) modeling, parametric optimization, and experimental examination of PEEK 3D printing were conducted to enhance 3D printing processes. In this study, four critical process factors (infill density, layer height, printing speed, and infill pattern) influence the surface roughness, mechanical strength, and elastic modulus of the printed samples. Utilizing a 4–12–3 network design, this study demonstrates that an ANN model with an average error of less than 5% is optimal for all three responses. Furthermore, the study employed a teaching and learning based optimization algorithm (TLBO) and a non-dominated sorting genetic algorithm (NSGA) to optimize the printing process to obtain improved mechanical properties. The findings highlight TLBO’s ability to minimize surface roughness to 6.01 μm and NSGA’s capability to maximize the elastic modulus to 1253.35 MPa and ultimate tensile strength to 65.55 MPa. Microstructural studies supported the results obtained through parametric analysis and optimization.

Enhancing bending strength in continuous drive friction welding of PEEK polymer cylinders through the innovative progressively increased welding area method

The continuous drive friction welding (CDFW) stands out for its low energy consumption within the welding realm. Polyetheretherketone (PEEK) represents a high-performance engineering thermoplastic, falling under the polyaryletherketone family. Renowned for its outstanding mechanical, thermal, and chemical attributes, PEEK finds utility across a diverse array of industries. However, the discovery of numerous voids at the weld interface has revealed limitations in the mechanical properties of PEEK welded samples. This study introduces an innovative approach named progressively increased welding area (PIWA) method, to mitigate voids within the weld interface. In general, the Taguchi method was used to optimize the process parameters of CDFW of dissimilar PEEK round rods to reduce random efforts by the trial-and-error method. It was found that the proposed PIWA method can definitely enhance the bending strength of rotational friction welded samples due to reduction of voids inside the weld interface. The optimal process parameters for the CDFW with the PIWA method involve a rotational speed of 2500 rpm, a cone angle of 120°, a cone top width of 8 mm, and a feed rate of 0.1 mm/s. The most influential factor affecting the bending strength of the PEEK welded samples is the feed rate, followed by cone angle, rotational speed, and cone top width. Specifically, the contribution ratios for feed rate, cone angle, rotational speed, and cone top width are about 71 %, 20 %, 7 %, and 2 %, respectively. The confirmation tests showed that the bending strength of the PEEK welded samples using optimal process parameters can be increased by approximately 68 % compared with the maximum bending strength of 180 MPa using the conventional method with a cone angle of 180° The proposed PIWA method has industrial applicability and practical value because this technique can enhance the mechanical properties of PEEK welded samples under low environmental pollution and energy consumption.

Ensembled surrogate-assisted material extrusion additive manufacturing for enhanced mechanical properties of PEEK

Purpose This study aims to improve the mechanical properties of an object produced by fused deposition modelling with high-grade polymer. Design/methodology/approach The study uses an ensembled surrogate-assisted evolutionary algorithm (SAEA) to optimize the process parameters for example, layer height, print speed, print direction and nozzle temperature for enhancing the mechanical properties of temperature-sensitive high-grade polymer poly-ether-ether-ketone (PEEK) in fused deposition modelling (FDM) 3D printing while considering print time as one of the important parameter. These models are integrated with an evolutionary algorithm to efficiently explore parameter space. The optimized parameters from the SAEA approach are compared with those obtained using the Gray Relational Analysis (GRA) Taguchi method serving as a benchmark. Later, the study also highlights the significant role of print direction in optimizing the mechanical properties of FDM 3D printed PEEK. Findings With the use of ensemble learning-based SAEA, one can successfully maximize the ultimate stress and percentage elongation with minimum print time. SAEA-based solution has 28.86% higher ultimate stress, 66.95% lower percentage of elongation and 7.14% lower print time in comparison to the benchmark result (GRA Taguchi method). Also, the results from the experimental investigation indicate that the print direction has a greater role in deciding the optimum value of mechanical properties for FDM 3D printed high-grade thermoplastic PEEK polymer. Research limitations/implications This study is valid for the parameter ranges, which are defined to conduct the experimentation. Practical implications This study has been conducted on the basis of taking only a few important process parameters as per the literatures and available scope of the study; however, there are many other parameters, e.g. wall thickness, road width, print orientation, fill pattern, roller speed, retraction, etc. which can be included to make a more comprehensive investigation and accuracy of the results for practical implementation. Originality/value This study deploys a novel meta-model-based optimization approach for enhancing the mechanical properties of high-grade thermoplastic polymers, which is rarely available in the published literature in the research domain.

In vitro Examination of the Bond Strength of PEEK and PEKK Materials Used as Substructure Materials with the Superstructure Composite before and after Artificial Aging and Examination of Scanning Electron Microscope Images

Abstract Objective This study aims to evaluate the bond strength of polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) materials when used as substructures with composite superstructures, before and after artificial aging. Surface treatments, including sanding and sandblasting, were examined to determine their impact on bond strength and surface topography. Materials and Methods Sixty samples, divided equally between PEEK and PEKK, were prepared. Each group was further divided into three subgroups (n = 10): control, 10,000 thermal cycles, and 30,000 thermal cycles. The samples were subjected to surface treatments using 600-, 800-, and 1,200-grit silicon carbide wet sandpaper, followed by air abrasion with 110 µm alumina particles. Bond strength tests were conducted using an INSTRON-3345 universal testing machine, and failure types were analyzed under a stereomicroscope. Results Sandblasting with 110 µm aluminum oxide (Al2O3) significantly increased the bond strength of both PEEK and PEKK materials compared with sanding. PEEK samples treated with sandblasting showed the highest bond strength (mean = 1.296 MPa), while PEKK samples treated with sanding had the lowest (mean = 0.056 MPa). Thermal cycling reduced bond strength in both materials, with a more pronounced decrease observed in the 30,000 cycle groups. analysis of variance results indicated significant differences in bond strength based on the material, surface treatment, and the interaction between these factors. Conclusion Sandblasting with 110 µm Al2O3 is an effective method for enhancing the bond strength of PEEK and PEKK substructures with composite materials. These findings support the continued use of PEEK and PEKK polymers in dental applications, suggesting that appropriate surface treatments can significantly improve clinical outcomes.

High-performance thermoplastic nanocomposites for aerospace applications: A review of synthesis, production, and analysis

Thermoset polymers are cured under natural or synthetic created conditions and retain their solid form when exposed to heat. Unlike thermosets, thermoplastics melt when exposed to heat after production. Thermoplastics are preferred as raw materials because they can be easily shaped after production, have a high shelf life and are recyclable. In this regard, the prominence of high-performance engineering polymers in recent years has led to the preference of alternative polymers to thermosets. High-performance engineering thermoplastics include thermoplastics such as polyphenylene-sulfide (PPS), polyether-ether-ketone (PEEK), polyether-ketone-ketone (PEKK), polyphenylene-ether, polysulfone,polyoxadiazole, polyimide, polyether-amide, polyether-amide-imide, polynaphthalene, and polyamide-imide. These polymers exhibit application potential in aerospace, defense, automotive, marine, energy, and medical sectors. In challenging conditions such as high pressure, temperature, and corrosive environments, they possess high service temperatures, enhanced mechanical and physical properties, preferable chemical resistance as well as out-of-autoclave and rapid processing properties. In this review article, nanomaterial production methods (bottom-up and top-bottom) are mentioned. In the following sections, PPS, PEEK, and PEKK thermoplastics are explained, and carbon- and boron-based nano additives used in constructing nanocomposites are investigated. In the last section, PPS, PEKK, and PEEK polymer nanocomposites are investigated.

Polyetheretherketone split post and core for restoration of multirooted molar with insufficient dental tissue remnants by digital techniques: a case report and 3-year follow up

BackgroundMulti-rooted teeth with extensive dental defects often face challenges in stability and biomechanical failure. High-performance polymer PEEK materials, with properties closer to dentin, show promise in reducing stress concentration and preserving tooth structure. This report aimed to explore the use of a highly retentive polyetheretherketone (PEEK) for manufacturing custom-made split post and core for the restoration of grossly destroyed endodontically treated molars.Clinical considerationsA 40-year-old female patient presented with complaints of loss of tooth substance in the posterior mandibular tooth. This case involved the digital design and fabrication of PEEK split post and core to restore multirooted molar with insufficient dental tissue remnants. The restorations were evaluated over a 3-year follow-up using the World Federation criteria (FDI). The restoration was clinically evaluated through intraoral examination, radiographic assessment, and subjective patient satisfaction, and was deemed clinically good according to FDI criteria.ConclusionThe outstanding mechanical properties of PEEK, coupled with the structure of the split post, provide an effective treatment option for weakened multirooted teeth. Simultaneously, the restoration configuration effectively addressed the challenge of varying postinsertion directions, and the interlocking mechanism between the primary and auxiliary posts enhanced the stability of the post and core.

Evaluation of Material Extrusion Printed PEEK Mold Inserts for Usage in Ceramic Injection Molding

The rapid tooling of mold inserts for injection molding allows for very fast product development, as well as a highly customized design. For this, a combination of rapid prototyping methods with suitable polymer materials, like the high-performance thermoplastic polymer polyetheretherketone (PEEK), should be applied. As a drawback, a huge processing temperature beyond 400 °C is necessary for material extrusion (MEX)-based 3D printing; here, Fused Filament Fabrication (FFF) requires a more sophisticated printing parameter investigation. In this work, suitable MEX printing strategies, covering printing parameters like printing temperature and speed, for the realization of two different mold insert surface geometries were evaluated, and the resulting print quality was inspected. As a proof of concept, ceramic injection molding was used for replication. Under consideration of the two different test structures, the ceramic feedstock could be replicated successfully and to an acceptable quality without significant mold insert deterioration.

Determination of “tribological performance working fields” for pure PEEK and PEEK composites under dry sliding conditions

Poly-ether-ether-ketone (PEEK) and PEEK composites are widely used polymers in many engineering applications where dry sliding is required. In this study, the influence of sliding velocity and applied load values on the friction and wear behavior of pure PEEK, 30 wt% glass fiber reinforced PEEK (PEEK-30GF), 30 wt% carbon fiber reinforced PEEK (PEEK-30CF) and 10 wt% carbon fiber+10 wt%graphite +10 wt%poly-tetra-fluoro-ethylene (PTFE) filled PEEK (ie. High (H) pressure (P) and velocity (V) resistant PEEK (PEEK-HPV)) composites rubbing against AISI 304 stainless steel disc was investigated. The experiments were carried out at room temperature under dry sliding conditions in a pin-on-disc wear rig. The applied loads ranged from 30 to 250 N, while the sliding velocities ranged from 1.0 to 4.0 m/s. At these load and velocity ranges, the friction coefficient-wear rate relationship of pure PEEK and composites was established and evaluated. In addition, the operating load-velocity limits of each material were determined and stated. The lowest coefficient of friction and wear rate were obtained in PEEK-HPV, PEEK-30CF, PEEK-30GF composites and pure PEEK polymer, respectively. In addition, it was observed that the coefficient of friction (CoF) decreased and the specific wear rate (SWR) increased with the increase in sliding velocity and applied load in all PEEK materials. The wear rate values of PEEK-HPV and PEEK-30%CF composites are in the range of 10−7 - 10−6 (mm3/Nm), while the wear rate values of pure PEEK and PEEK-30%GF are in the range of 10−6 - 10−5 (mm3/Nm). It was determined that carbon fiber, graphite and PTFE additives added to PEEK polymer as hybrid were very effective in reducing the wear rate of PEEK composite (PEEK-HPV). An adhesive wear mechanism was observed in PEEK-HPV and PEEK-30CF composites both at low load and velocity values and at high load and velocity values.

Effect of cement volume on biomechanical response of a spine segment treated with a PEEK polymer implant: a finite element comparative study with vertebroplasty.

In the current study, a 3D finite element study was performed to investigate the biomechanical response of an osteoporotic spine segment treated with a novel transpedicular implant (V-STRUT©, Hyprevention, France) made of PEEK (polyetheretherketone) material combined with either injections of 2, 3, 4, 5 and 6 cc of cement. The objective was to assess numerically the biomechanical performance of the implant in combination with different doses of the injected bone cement and to compare its performance with the gold standard vertebroplasty (VP) technique. A female (69yo) was selected and a 3D finite element model of an osteoporotic spine segment was built based on a Computed Tomography (CT) scan performed from T12 to L2 with corresponding intervertebral discs and ligaments. A heterogeneous distribution of bone material properties was assigned to the bone using grey scale levels. Bilateral ellipsoid geometries of the inserted cement were retained for the V-STRUT and VP models based on experimental observation performed on different patients treated with the V-STRUT device. The current study demonstrated an optimal dose of 4 cc of bilaterally injected cement for the V-STRUT and VP techniques to restore the treated segment and confirmed that the V-STRUT device in combination with bone cement is superior to VP alone in establishing the normal stiffness and in reducing the applied stress to the immediately adjacent vertebral levels.

The Effects of Different Beverages on Fracture Resistance of CAD/CAM Monolithic PEEK and Monolithic Zirconia Crowns

Aim: To assess the impact of various beverages on the fracture resistance of CAD/CAM polyetheretherketone (PEEK) and monolithic zirconia materials. Materials and Method: We fabricated eighty CAD/CAM materials from PEEK polymer (CopraPeek; Whitepeaks Dental Solutions GmbH, Germany) and monolithic zirconia (inCoris TZI; Dentsply Sirona Systems GmbH, Bensheim, Germany), with ten samples per group. These samples were submerged in either distilled water, cola, coffee, or red wine and stored at 37°C for 12 days. We utilized a universal testing machine (Lloyd LRX; Lloyd Instruments Ltd., West Sussex, UK) to measure each sample’s fracture resistance. The t-test provided a comparison of normally distributed variables between the two groups. For multiple group comparisons, we executed an analysis of variance (ANOVA). Results: A statistically significant difference was observed between the PEEK and zirconia groups in terms of maximum load and elastic load-bearing capacity values (p˂0.05), with zirconia materials yielding higher values. However, there was no critical difference in these measures obtained from different solutions for neither PEEK nor zirconia samples (p>0.05). Conclusion: CAD/CAM monolithic PEEK material stored in various solutions demonstrated lower fracture resistance and elastic strength than monolithic zirconia materials. Despite this, PEEK exhibited the highest fracture resistance to intraoral occlusal forces. Accordingly, due to its chemically inert nature and superior force absorption, we recommend PEEK as a viable alternative material for posterior crowns in fixed restorations.

Role of Polyetheretherketone in Prosthodontics: A Literature Review.

Implant prostheses and other fixed and removable metal prostheses have led to an increase in demand for the development of new and efficient materials such as high-performance polymers polyetheretherketone (PEEK) over titanium and other metals because of their further complications in the human body. PEEK is a polymer that is nontoxic and has a modulus of elasticity that is comparable to that of human bone. PEEK implants provide benefits over metal implants, such as reducing the stress shielding effect, simple processing, and color resemblance to natural teeth. And it is a fantastic alternative to titanium for dental and orthopedic implants. The current review is undertaken to understand the properties of this PEEK material to weigh its benefits and drawbacks for potential use in dental implants and other prostheses.

Tribological and mechanical characterization of carbon-nanostructures based PEEK nanocomposites under extreme conditions for advanced bearings: A molecular dynamics study

Polyetheretherketone (PEEK) carbon nanomaterial-based nanocomposites, incorporating zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D) and three-dimensional (3D) carbon structures have gained prominence as advanced materials with the potential to enhance tribological properties paving the way for a new era in the development of advanced bearings for high-performance machinery applications. This study delves into the forefront of friction and wear analysis, employing all atom molecular dynamics (aa-MD) simulations to engineer PEEK polymer nanocomposites with precision under elevated temperature and higher velocity. The research presents optimization of mechanical strength and tribological properties crucial to meet the demanding requirements of industrial machinery. The addition of C60 fullerenes reduced COF by 16.59% and wear rates by 6.52% due to its spherical shape and lubrication effects. Introduction of carbon-nanotubes further decreased COF by 54.54% and wear rates by 32.5%, offering resistance to abrasive and adhesive wear. S-graphene showed notable performance, reducing COF by 69.40% and wear rates by 75.03%, making it promising for sliding and wear applications. Carbon-nanocones reduced COF by 60.6% and wear rates by 72.06%, slightly higher than S-Gr due to abrasive effects and increased surface contact. These findings underscore the potential of reinforcement dimensionality in enhancing the tribological properties of PEEK based nanocomposites.

Evaluation of High-Performance Polyether Ether Ketone Polymer Treated with Piranha Solution and Epigallocatechin-3-Gallate Coating.

Dental implantation has become a standard procedure with high success rates, relying on achieving osseointegration between the implant surface and surrounding bone tissue. Polyether ether ketone (PEEK) is a promising alternative to traditional dental implant materials like titanium, but its osseointegration capabilities are limited due to its hydrophobic nature and reduced surface roughness. The aim of the study is to increase the surface roughness and hydrophilicity of PEEK by treating the surface with piranha solution and then coating the surface with epigallocatechin-3-gallate (EGCG) by electrospraying technique. The study includes four groups intended to investigate the effect of piranha treatment and EGCG coating: a control group of PEEK discs with no treatment (C), PEEK samples treated with piranha solution (P), a group of PEEK samples coated with EGCG (E), and a group of PEEK samples treated with piranha solution and coated with EGCG (PE). Surface roughness, wettability, and microhardness were assessed through statistical analysis. Piranha treatment increased surface roughness, while EGCG coating moderated it, resulting in an intermediate roughness in the PE group. EGCG significantly improved wettability, as indicated by the reduced contact angle. Microhardness increased by about 20% in EGCG-coated groups compared to noncoated groups. Statistical analysis confirmed significant differences between groups in all tests. This study demonstrates the potential of EGCG coating to enhance the surface properties of PEEK as dental implants. The combined piranha and EGCG modification approach shows promise for improved osseointegration, although further vivo research is necessary. Surface modification techniques hold the key to optimizing biomaterial performance, bridging the gap between laboratory findings and clinical implementation in dental implantology.

Polyetheretherketone Polymer Transpedicular Vertebral System to Treat Vertebral Compression Fracture: A Multicentre Pilot Study of Feasibility and Safety.

To prospectively evaluate the feasibility and safety of a polyetheretherketone (PEEK) polymer transpedicular vertebral system to treat vertebral compression fracture (VCF). Nine consecutive patients (4 men and 5 women; median age 59 [interquartile range: 58-64 years]) were included. The procedure duration, length of hospital stay, and complications were reported. Visual analog scale (VAS) and the Oswestry disability index (ODI) for pain and disability were assessed before and at 2, 6, and 12-month after the procedure. The procedure was technically feasible in all patients. The median procedural time was 64 minutes [45-94]. Only minor adverse events were reported (5 clinically asymptomatic cement leakages) but no severe complications. No post procedural adjacent fracture was reported during follow-up (median: 193 days [147-279]). The median VAS score decreased from 55 mm [50-70] before the procedure to 25 mm [5-30] at 2-month (P = .0003) and 30 mm [15-40] at 6-month follow-up (P = .14). The median ODI decreased from 23% [19-26] before the procedure to 12% [10-14] at 2-month (P = .03) and 12% [9-20] at 6-month follow-up (P = .47). Percutaneous transpedicular fixation of VCF by PEEK implants appears feasible and safe.

Glycerol aqueous solutions for the enhanced tribological behaviour of polymer composites sliding against steel

In this study the potential benefits of using glycerol solutions containing 20%, 40%, 60%, or 80% water as environmentally adapted lubricants (EALs) on the tribological properties of polyoxymethylene (POM) and polyetheretherketone (PEEK) polymer composites was examined. For comparative purposes, pure glycerol and water were used. The friction and wear mechanisms of three different polymer composites were analysed: PEEK CF30 (PEEK reinforced with 30% carbon fibre), PEEK MOD (PEEK reinforced with 10% carbon fibre, 10% graphite and 10% polytetrafluoroethylene), and POM CF30 (POM with 30% carbon fibre). The tribological measurements were performed under reciprocating sliding conditions with a steel ball on a polymer plate. For all the composites in glycerol and in glycerol with up to 40% water the coefficient of friction was low (∼ 0.02). The specific wear rate was also low and about the same for all polymers, of the order of 10−8 mm3/(Nm). However, at higher water contents (80% of water and pure water) both the coefficient of friction and the specific wear rate increased and a transfer film formed on the steel counterparts. In the lubricant with a higher water content the PEEK CF30 showed the lowest specific wear-rate increase (24 times in the lubricant with 80% water), followed by the POM CF30 (52 times in the lubricant with 80% water). At higher water contents the POM CF30 showed the smallest increase in the coefficient of friction (3.6 times in the lubricant with 80% water), an increase up to two times less than for the PEEK polymers.

Preparation and characterization of transparent polyetherketone

AbstractTransparent polymer with excellent heat resistance and mechanical properties play an important role in many fields. However, transparent polyetheretherketones films are rarely reported, probably due to their high crystallinity. In this work, a transparent polymer polyetherketone was prepared from the reaction of 4,4′‐difluorobenzophenone, 2,6‐bis(4‐hydroxybenzylidene) cyclohexanone, and tert‐butylhydroquinone in the presence of K2CO3. This new polymer has excellent thermal stability, high glass transition temperature (Tg = 172°C), good film‐casting property, high transparency, good hydrophobicity, and low saturated water absorption (0.52%). The material has broad application prospects in flexible solar cells, UV protection, and thin insulation materials.

Characterization of the Polyetheretherketone Weldment Fabricated via Rotary Friction Welding.

Polyether ether ketone (PEEK) is frequently employed in biomedical engineering due to its biocompatibility. Traditionally, PEEK manufacturing methods involve injection molding, compression molding, additive manufacturing, or incremental sheet forming. Few studies have focused on rotational friction welding (RFW) with PEEK plastics. Based on years of RFW practical experience, the mechanical properties of the weldment are related to the burn-off length. However, few studies have focused on this issue. Therefore, the main objective of this study is to assess the effects of burn-off length on the mechanical properties of the welded parts using PEEK polymer rods. The welding pressure can be determined by the rotational speed according to the proposed prediction equation. The burn-off length of 1.6 mm seems to be an optimal burn-off length for RFW. For the rotational speed of 1000 rpm, the average bending strength of the welded parts was increased from 108 MPa to 160 Mpa, when the burn-off length was increased from 1 mm to 1.6 mm and the cycle time of RFW was reduced from 80 s to 76 s. A saving in the cycle time of RFW of about 5% can be obtained. The bending strength of the welded part using laser welding is lower than that using RFW, because only the peripheral material of the PEEK cylinder was melted by the laser.