Polyetheretherketone Resin Research Articles

A “sizing-free” strategy to improve the interfacial property of PEEK/CF composites based on “grafting-bridging” bifunctional diazonium salt

Achieving simple and efficient interfacial modification between carbon fiber and polyether ether ketone (PEEK) has been the pursuit of researchers. In this study, by comparing the nucleophilicity of various aromatic amines, a direct Schiff base reaction with polyether ether ketone (PEEK) has been achieved. Based on this, a “grafting-bridging” bifunctional diazonium salt containing a phenylethylamine structure was designed and synthesized to enhance the interfacial strength through covalent bonding without the use of sizing agents. The diazonium salt was grafted onto the surface of carbon fiber through electrochemical reduction, while the PEEK resin and phenylethylamine could achieve bridging through heat treatment, thus a PEEK/CF interface with enhanced covalent bonds was constructed. The reaction and conversion rate between phenylethylamine and PEEK resin were confirmed through IR and NMR. The successful grafting of the diazonium salt on the carbon fiber was determined through XPS and cyclic voltammetry. The bridging reaction on the surface of carbon fiber was verified through XPS and the use of 6F-PEEK with characteristic elements. As a result, the interfacial shear strength (IFSS) of the modified PEEK/CF interface reached 86.2 MPa, representing a 102.8 % improvement compared to the untreated interface of 42.5 MPa, fully demonstrating the excellent effect of the bifunctional diazonium salt.

Carbon fiber‐reinforced thermoplastic synthesized by the hypercrosslinking reaction of polyether ether ketone

AbstractRecently, thermoplastic resins were used as matrix to synthesize carbon fiber‐reinforced thermoplastic (CFRTP) for recycling it easily. In this study, a CFRTP with excellent mechanical properties and heat resistance was synthesized using a polyether ether ketone (PEEK) as a matrix resin. The PEEK resin was modified to form cross‐linked structures through Friedel–Crafts reaction alkylation. The synthesis temperature of CFRTP was optimized considering the mechanical properties of PEEK, and its heat resistance was enhanced because of the cross‐linked structures. Further, the cross‐linked PEEK resin was partially used as a matrix resin, and the mechanical properties of the CFRTP were enhanced. We plan to develop a method for recycling CFRTP using PEEK and crosslinked PEEK for synthesizing C/C composites by focusing on the high heat resistance of the crosslinked PEEK containing a large amount of carbon and reducing mass loss after heat treatment.Highlights CC bonds were introduced into the polyether ether ketone (PEEK) resin by Friedel–Crafts reaction alkylation. Thermal properties of PEEK were enhanced by hypercrosslinking reaction. Optimization of synthesized temperature was investigated to fabricate carbon fiber‐reinforced thermoplastic (CFRTP). Mechanical properties were enhanced CFRTP modified with hypercrosslinking reaction.

Effect of different surface roughening treatment on polyether ether ketone and acrylic resin bonding: A pilot study.

As polyether ether ketone (PEEK) is a relatively new material in dentistry, its bonding properties with regard to dental acrylic base materials are not fully known. To ensure the long-term success of removable dentures with a PEEK framework, the base materials must be well bonded to each other. The study aimed to investigate the effects of different kinds of surface roughening treatment on PEEK and acrylic resin bonding. Eighty PEEK specimens (N = 80) were randomly divided into 5 groups (n = 16 per group) and subjected to various surface roughening treatment (control, grinding, sandblasting, tribochemical silica coating (CoJet), and sulfuric acid etching). Heat-polymerized acrylic resin was applied to the treated surfaces of the PEEK specimens. The shear bond strength (SBS) test, environmental scanning electron microscopy (ESEM) analysis and three-dimensional (3D) surface topography analysis were performed. The statistical analysis of the data was conducted using the analysis of variance (ANOVA) and Tukey's multiple comparison test. The one-way ANOVA showed significant differences in the SBS values between the groups (p = 0.001). Sandblasting, tribochemical silica coating and sulfuric acid etching resulted in high SBS values (p = 0.001). The highest SBS values were observed in the sulfuric acid etching group (8.83 ±3.63 MPa), while the lowest SBS values were observed in the control group (3.33 ±2.50 MPa). The additional roughening treatment applied to the PEEK surface increases the bond strength with heat-polymerized acrylic resin.

Enhanced interfacial bonding of AF/PEEK composite based on CNT/aramid nanofiber multiscale flexible-rigid structure

The application of aramid fiber (AF)/polyetheretherketone (PEEK) composites is currently hindered by the inert surface and poor wettability of AF, resulting in weak interfacial adhesion and poor mechanical properties. Surface coating and the introduction of nanostructures have been proven to be effective approaches to address this problem. Herein, a simple hybrid sizing agent has been developed to modify the AF surface, consisting of soluble polyimide (PI) as a compatibilizer, carboxyl-functionalized carbon nanotubes (CNT-COOH) as a rigid unit, and aramid nanofibers (ANF) as a flexible component. The synergetic effects of PI and the multiscale flexible-rigid structure (CNT-COOH/ANF) contribute to the formation of chemical and physical bonds between AF and PEEK matrix, further improving the interfacial adhesion and stress transfer efficiency. Attributed to the enhanced wettability and roughness of AF, compared with unsized AF, the flexural strength (220.97 MPa), modulus (13.26 GPa), ILSS (13.36 MPa), and storage modulus (12.93 GPa) of the AF/PEEK composite increase by 132.60 %, 99.00 %, 18.97 %, and 82.70 % respectively. Additionally, the flexible-rigid nanonetwork facilitates the penetration of the PEEK resin into pore spaces. This simple and effective approach exhibits promising potential in enhancing the interfacial bonding of AF/PEEK composites.

Study on the stability of high solid content polyether‐ether‐ketone aqueous suspension

AbstractCarbon fiber (CF) reinforced polyether‐ether‐ketone (PEEK) composite is found extensive application in various industries. Efforts have been made to enhance the interfacial binding between the resin and fibers. Herein, we report a green CF surface modification suspension coating method that could resist high process temperature by optimizing the stability of the aqueous suspension, which contains PEEK resin particles and a mixture of sodium dodecyl sulfate (SDS) and polyethylene glycol monostearate (stPEG). The optimized suspension (PEEK: SDS mass ratio= 5:1) that can meet around 500°C process requirement was then used to improve the physical interfacial binding between CF and PEEK. Based on the suspension colloidal stability, the process was optimized by tensile tests of the CF/PEEK monofilaments. The results show that the colloidal stability of the PEEK aqueous suspension with a total solid content of 20 wt.% containing stPEG‐SDS (stPEG: SDS mass ratio= 1:2) surfactant blend (PEEK: stPEG‐SDS mass ratio= 5:1) reached the optimum at a stirring rate of 750 rpm. The maximum tensile strength of the CF/PEEK monofilaments reached ~4.968 GPa at a coating diameter of 8.54 μm. This PEEK aqueous suspension provides a non‐toxic, environmentally friendly and high temperature resistant aqueous material to produce high‐performance fiber reinforced PEEK composites.

The optimization of thermo-compression process parameters of continuous carbon fiber reinforced PEEK composites

Thermoplastic composites with high performance have become the primary material developed for aerospace applications. However, there are still numerous challenges for high-quality thermo-compression molding of thermoplastic composites. This paper investigated the control mechanism of porosity in continuous carbon fiber (CCF) reinforced polyether-ether-ketone (PEEK) composites based on an orthogonal molding scheme, which examines the effect of thermo-compression process parameters on porosity. Further insights were obtained regarding the correlation among molding process parameters, porosity, and mechanical properties. The experimental results indicated that the significant factors affecting the bending performance of CCF/PEEK composites were molding pressure, temperature, and sequence holding time. Moreover, the viscosity of molten PEEK resin significantly affected the porosity of the composites, and the descending order of effect on the porosity of the composites was molding temperature, holding time, and molding pressure. Based on these results, we identified the optimal molding process conditions for CCF/PEEK composites, which were 405 °C, 1.5 MPa, and 30 min.

Effect of laser surface treatment on shear bond strength between polyetheretherketone and heat-activated polymethylmethacrylate resin.

To compare the shear bond strength between polyetheretherketone (PEEK) and heat activated polymethylmethacrylate (PMMA) resin after laser treatment. A total of 128 PEEK discs were fabricated (10mm diameter and 2mm thickness) and allocated into two groups. Group 1 was subjected to surface treatment followed by thermal cycling for 5000 cycles and group 2 was subjected to surface treatment followed by thermal cycling for 10,000 cycles. Each group was further subdivided into four subgroups (n = 16) which were: no surface treatment; primer treatment; acid etching; and laser surface treatment. PEEK was then bonded with PMMA resin using the conventional flasking technique. The shear bond strength was evaluated using a universal testing machine with a crosshead speed of 1mm/min. Statistical analysis was done using one-way ANOVA for comparing within groups, followed by Tukey HSD test. Student's T-test was done to evaluate between the two groups. In group 1, the highest shear bond strength was exhibited by the laser group (19.08 ±0.16MPa) followed by the acid etch group (14.84 ±0.23MPa), and the primer group (6.43 ±0.20MPa), while the least shear bond strength was observed in the no surface treatment group (4.98 ±0.34MPa) which was found to be significant (p<0.05). In group 2, the highest shear bond strength was observed in the laser group (18.21±0.23MPa) followed by the acid etch group (13.77±0.48MPa), and the primer group (6.04±0.11MPa), while the least shear bond strength was observed in no surface treatment group (4.35±0.21MPa) which was found to be significant (p<0.05). The shear bond strength between PEEK and PMMA resin was highest for specimens that were surface treated with laser and followed by specimens treated with acid etching, primer application, and without surface treatment, respectively. Increasing thermal cycling from 5000 cycles to 10,000 cycles also reduced the bond strength.

Effect of Various Airborne Particle Abrasion Conditions on Bonding between Polyether-Ether-Ketone (PEEK) and Dental Resin Cement.

The effects of alumina particle size and jet pressure on the bond strength of polyetheretherketone (PEEK) were examined to determine the airborne particle abrasion parameters with minimal effects on PEEK and to achieve optimal bond strength, as a reference for future clinical use. An alumina particle with four particle sizes and three jet pressures was used to air-abrade PEEK. Surface roughness (Ra), morphology, chemical structure, and wettability were analyzed using a stylus profilometer, scanning electron microscope, X-ray diffractometer, and contact angle analyzer, respectively. The shear bond strength (SBS) of PEEK and dental resin cement was analyzed using a universal testing machine (n = 10). The failure modes and debonded fracture surfaces were observed using optical microscopy. Airborne particle abrasion increased the Ra and hydrophobicity of PEEK and deposited alumina residues. The SBS generally decreased after thermal cycling. A large particle size damaged the PEEK surface. The effects of different particle sizes and jet pressures on the SBS were only significant in certain groups. Adhesive failure was the main mode for all groups. Within the limitations of this study, 110 μm grain-sized alumina particles combined with a jet pressure of 2 bar prevented damage to PEEK, providing sufficient SBS and bonding durability between PEEK and dental resin cement.

The mix-mode fracture behaviour of aerospace composite joints co-cured by different forms of advanced thermoplastics

The co-cure joining of thermoset composites by thermoplastics is an advanced approach to develop robust composite joints. Herein, Polyethylenimine (PEI) and Polyetheretherketone (PEEK) polymers in a form of film, woven mesh, hollow mesh and carbon fibre reinforced plastic were utilised as interlayers for the co-cure joining of an aerospace composite. A cracked-lap shear test was used to investigate the fracture toughness and mechanisms of the co-cured composite joints under a mixed mode-I/II loading condition. The experimental results revealed that the insert of PEI and PEEK interlayers significantly enhanced the mix-mode crack resistance of the composite joints by different levels. The most remarkable increase in the crack initiation energy and crack propagation energy was 161% and 613%, respectively, that were obtained by adding the PEEK film interlayers. The main toughening mechanisms of the PEI film joined composites were crack-pining and matrix toughening of the PEI particles, which were formed by the diffusion of the PEI resins into the composite epoxy matrix during the curing process. Plastic deformation and fracture of the PEEK resins were the main toughening mechanisms of the composites that were co-cure joined by the PEEK films, woven meshes, hollow meshes and carbon fibre reinforced tapes. The crack resistance of the composite joints correlated well with the level of the PEEK fracture phenomena during the mix-mode fracture process.

Crystallization kinetics of glass fiber filled poly(ether ether ketone) with nanogram sample size: Feasibility study for fast scanning calorimetry

The feasibility of using FSC for fiber-filled polymer composites is questionable since the typical FSC sample thickness is comparable to the fiber diameter. In this study, X-ray computed tomography (XCT) with an ultra-high-resolution was performed to reconstruct the interior structure of poly(ether ether) ketone (PEEK) composite pellets. Using reconstructed 3D XCT matrices of PEEK resin, glass fibers, and voids, PEEK pellets sliced with different directions and sampling frequencies were analyzed to mimic FSC sample preparation. For the sample thicknesses less than 50 μm, PEEK samples sliced perpendicular to the fiber flow direction had good filler homogeneity and always had a lower coefficient of variation than pellets sliced along the fiber flow direction. This conclusion is later supported by the isothermal crystallization kinetics of PEEK and its composites investigated by differential scanning calorimetry and fast scanning calorimetry over a wide temperature range relevant to processing.

Comparison of marginal and internal adaptation of three-unit fixed dental prostheses made using CAD/CAM metal-free materials.

The aim of this study was to compare the marginal and internal adaptation of three-unit fixed dental prostheses (FDPs) fabricated from different metal-free materials using CAD/CAM methods. A total of 100 three-unit FDPs were produced from a cubic zirconia, a fiber-reinforced resin composite, a polyetheretherketone (PEEK), a polyetherketoneketone (PEKK), and a polymer composite material by the CAD/CAM method (n = 20 per material). The zirconia group was considered the control/reference material. Marginal and internal gap values of the produced FDPs were measured using the silicone replica method at ×40 magnification under a stereomicroscope. The obtained data were analyzed using one-way ANOVA and Tukey's HSD tests. The marginal and internal gap values for the cubic zirconia material were found to be statistically significantly lower than those seen for the PEEK, polymer composite, PEKK, and fiber-reinforced resin composite materials. While the marginal and internal adaptation of the cubic zirconia material was found to be better than the others, it should be noted that the marginal and internal gap values for all other materials tested were found to be within the clinically acceptable range.

High-Precision Small-Diameter Deep Hole Drilling Using Cooling and Step Feed in PEEK Resin

The objective of this study is to achieve a high-precision and high-efficiency machining process for industrial components of the polyether ether ketone (PEEK) resin, such as the inspection socket of a connector or semiconductor packages. However, the drilling of holes in PEEK resin is challenging. Because PEEK resin is a thermoplastic resin, it can soften or melt owing to the heat generated during processing, which causes burrs and degrades the accuracy of the machined hole, thereby resulting in quality deterioration and hindering post-processing. Since the thermal conductivity of plastic materials including PEEK resin is lower than those of metals, the heat generated during processing does not dissipate to the outside of the workpiece, and the effect of the processing temperature on the processing accuracy is significant, particularly during drilling. Hence, a workpiece is cooled via a cold gas supply in this study. The effect of cold gas cooling on the machined hole accuracy and cutting state in the small-hole machining of PEEK resin is investigated. Results show that cooling the workpiece effectively decreases the cutting temperature and improves the machined hole accuracy. Under the experimental conditions, the combination of nonstep drilling and cooling enables high-precision drilling at approximately the same accuracy as step drilling.

Nd:YVO4 laser groove treatment can improve the shear bond strength between dental PEEK and adhesive resin cement with an adhesive system.

The purpose of this study was to investigate the effect of various surface treatments on the shear bond strength between dental polyetheretherketone (PEEK) and adhesive resin cement. Two hundred and forty specimens were randomly classified into four groups: no treatment, sandblasted, sulfuric-acid-etched, and laser-grooved treatment. Each group was classified into two adhesive resin cement subgroups. Surface roughness, water contact angle, shear bond strength, and failure mode were measured; SEM and XPS results were obtained. The data were statistically analyzed using one-way or two-way analysis of variance and Tukey's honest significant difference test (α=0.05). Laser-grooved PEEK surface showed regular grooves and carbonization by thermal degradation; the surface roughness as well as water contact angle of were the highest in all groups. Shear bond strength values were significantly higher in the laser-groove-treated and sulfuric-acid-etched groups. Laser-groove-treated specimens showed cohesive failure. Laser-grooved treatment can improve shear bond strength between PEEK and adhesive resin cement.

Additively manufactured short carbon fiber reinforced polyetheretherketone by coating polyetherimide at the interface using fused filament fabrication

AbstractThe poor interfacial interactions and bonding between short carbon fibers (CFs) and polyetheretherketone (PEEK) resin matrix is a great challenge to manufacture high‐performance 3D printed CF/PEEK composites. Therefore, this paper presents a research focusing on the compatibility of CFs and PEEK. We propose an effective method to graft polyetherimide (PEI) onto activated CFs, then, composite filaments with modified fiber contents of 2.5%, 5%, 7.5% and 10% were prepared using fused filament fabrication (FFF). The chemical structures and surface morphologies of modified CFs were characterized, and the rougher surfaces with more polar groups can enhance the wettability of these CFs, which is improve the physical adhesion with PEEK. The thermal properties and mechanical properties of CF/PEEK composites within different carbon fiber contents were investigated. The results show that the tensile strength, flexural strength and interlaminar shear strength (ILSS) of 3D printed 5 wt% PEI@CF/PEEK parts were greatly improved by 40.85% (92.4 MPa), 35.70% (151.3 MPa) and 130.22% (26.59 MPa), respectively, which caused by the improvement of interfacial adhesion between CFs and PEEK resin. The results suggested that this modification is an effective approach to coating PEI on the surface of carbon fiber and enhance the mechanical properties of 3D printed PEEK composites. This method provides new insights for fabricating high‐performance 3D printed thermoplastic composites.

Effect of Surface Treatments on Shear Bond Strength of Polyetheretherketone to Autopolymerizing Resin.

These days, new prosthodontic materials are appearing with the development of digitalization. Among these, the use of polyetheretherketone (PEEK) as the clasp of removable partial dentures has been proposed. The adhesive strength between the PEEK and acrylic resin influences the probability of denture fracture. To investigate the effect of PEEK surface treatments on the shear bond strength to acrylic resin, five surface treatment conditions of PEEK were analyzed: 1. no treatment; 2. ceramic primer application; 3. Al2O3 sandblasting; 4. Rocatec; and 5. Rocatec with ceramic primer application, comparing with a metal primer-treated Co-Cr alloy. Two kinds of autopolymerizing resin (Unifast II and Palapress Vario) were used as bonding materials. The specimens were evaluated to determine the bond strength. Rocatec treatment with ceramic primer application yielded the highest bond strengths (12.71 MPa and 15.32 MPa, respectively, for Unifast II and Palapress Vario). When compared to a metal primer-treated Co-Cr alloy, the bond strength of PEEK to Unifast II was similar, whereas it was about 60% of that to Palapress Vario. Rocatec treatment, combined with ceramic primer, showed the highest bond strength of PEEK to acrylic resin. Treatment of PEEK will enable its use as the clasp of removable dentures and the fixation of PEEK prostheses.

Biomechanical Behavior of Tooth-Supported Fixed Partial Prostheses Components with Two Different Infrastructures: Metal and Polyether Ether Ketone (Peek).

This study uses the finite element method to assess the biomechanical behavior of tooth-supported fixed partial prostheses components manufactured with two different infrastructures: Cr-Co Fit Flex metallic alloy and Polyether Ether Ketone (PEEK) subjected to physiological occlusal loads. Two models with equal geometry were simulated-Model M1: fixed partial prosthesis with Cr-Co metallic infrastructure and feldspar ceramics coating Noritake Ex-3; Model M2: fixed partial prosthesis with PEEK infrastructure PEEK and indirect resin coating Sinfony. They were subjected to axial and oblique loads. The 3D models were entered in the software CAD Solidworks 2016 for registry and analysis. Data were analyzed according to the studied factors: dentin behavior, infrastructure, aesthetic coating, detachment pressure between tooth and cement, and tensile stress of cement. Most stress peaks were observed in model M2, but values from the two models were close. Model M1 showed better results in four of the factors: dentin, infrastructure, detachment pressure between tooth and cement, and cement tensile stress. Model M2 showed better performance in terms of the aesthetic coating. Similar values for both models in most of the simulations suggest a long lifespan of both treatments, although longer for model M1.

The analysis of welding and riveting hybrid bonding joint of aluminum alloy and polyether-ether-ketone composites

The aluminum alloy and the polyether-ether-ketone (PEEK) composites was joined by a new kind of hybrid welding technology, which combined the welding and riveting joining methods. The laser-TIG hybrid welding source and the stepped rivet were used in the experiments, in order to control the heat influence on the carbon particle reinforced PEEK (CPRP) in welding process. The microstructure of the joint was observed by SEM and EPMA. It was found that the structure of CPRP was not obviously influenced by the welding thermal effect, and only a few bubbles were found approaching the interface. There were three kinds of bonding modes in the hybrid joint, which made synergy effect on the property of the joint. The Aluminum welding joint and riveting joint decided the property of the hybrid bonding joint. The mechanical bonding and interface chemical reaction improved the interface structure between aluminum alloy and the PEEK resin matrix.

Effect of Various Treatment Modalities on Surface Characteristics and Shear Bond Strengths of Polyetheretherketone-Based Core Materials.

To investigate the effect of different surface treatments on the surface roughness (Ra), wettability, and shear bond strength of polyetheretherketone (PEEK) to composite resin. One hundred ninety eight PEEK specimens were divided into six groups (n = 33). Specimen surfaces were treated with the following surface treatment modalities: silicoating (CoJet), acetone treatment, acid etching (H2 SO4 ), airborne particle abrasion (Al2 O3 ), laser irradiation (Yb:PL laser), and the nontreated surface serving as the control. Surface roughness was measured with an profilometer (n = 11) and a goniometer was used to measure the surface wettability through contact angle (θ)(n = 11). PEEK surfaces were veneered with a composite resin (n = 11). The specimens were then thermocycled for 10,000 cycles at 5 to 55°C. Shear bond strengths between the PEEK and composite resin were measured with an universal test machine. One-way ANOVA was used to analyze the data. Tukey's post-hoc test was used to determine significant differences between groups (α = 0.05). Surface roughness and wettability of PEEK surfaces along with shear bond strength of PEEK to composite resin were influenced by the surface treatments. (p < 0.01) Highest mean Ra values were obtained for PEEK surfaces treated by laser irradiation (2.85 ± 0.2 µm) followed by airborne particle abrasion (2.26 ± 0.33 µm), whereas other surface treatment modalities provided similar Ra values, with the acid-etched PEEK surfaces having the lowest mean Ra values (0.35 ± 0.14 µm). Silicoating provided the most wettable PEEK surfaces (48.04 ± 6.28º), followed by either acetone treatment (70.19 ± 4.49º) or acid treatment (76.07 ± 6.61º). Decreased wettability was observed for airborne particle abraded (84.83 ± 4.56º) and laser-treated PEEK surfaces (103.06 ± 4.88º). The highest mean shear bond strength values were observed for acid-etched PEEK surfaces (15.82 ± 4.23 MPa) followed by laser irradiated (11.46 ± 1.97 MPa), airborne particle abraded (10.81 ± 3.06 MPa), and silicoated PEEK surfaces (8.07 ± 2.54 MPa). Acetone-treated (5.98 ± 1.54 MPa) and untreated PEEK surfaces (5.09 ± 2.14 MPa) provided the lowest mean shear bond strengths. The highest mean shear bond strengths were observed for acid-etched PEEK surfaces, followed by laser-irradiated, airborne particle abraded, and silicoated PEEK surfaces providing similar mean shear bond strengths. Since shear bond strengths higher than 10 MPa are considered acceptable, acid etching, laser irradiation, and airborne particle abrasion of PEEK surfaces may be considered viable surface treatment modalities for the PEEK material tested.

Structure-property relationships in commercial polyetheretherketone resins

Key relationships between molecular structure and final properties are reported for standard flow and high flow grades of commercially-available polyetheretherketone (PEEK) resins that differ primarily in molecular weight and molecular weight distribution. Despite similar chemistry and composition, the molecular size-dependent structural differences associated with the PEEK resins in this study are shown to influence the crystallization rate, final crystallinity, and melt rheology during processing, which subsequently affects mechanical properties, including strength, ductility, and impact resistance. These structure-property relationships provide fundamental understanding to aid in the design and manufacturing of industrial and medical devices that leverage both the advantages common to all PEEK resins, including chemical and thermal resistance, mechanical strength, and biocompatibility, as well as more subtle differences in crystallization kinetics, melt rheology, ductility, and impact resistance. POLYM. ENG. SCI., 57:955–964, 2017. © 2016 Society of Plastics Engineers

A214 水およびアンモニアの沸騰熱伝達とその経年変化に及ぼす界面活性剤とPEEK樹脂コーティングの影響

A long - term change of nucleate boiling heat transfer coefficients in water and ammonia have been measured when a surface active agent was added into water and those have been measured on a heated wire that PEEK (Poly Ether Ether Ketone) resin was coated in ammonia. The experiment has been carried out using a thermosyphon with a plain heated surface and a pool boiling vessel with a heated fine wire. The effect of the surface - active agent and PEEK coating on the nucleate boiling heat transfer coefficient and time variation of the nucleate boiling heat transfer coefficient were investigated experimentally for the surfactant concentration, Cs=0 and 1000 ppm. The result shows that the nucleate boiling heat transfer coefficient never changes for a month in pure water and in ammonia with the heated wire coated by PEEK resin. On the other hand, the boiling heat transfer coefficient decreases gradually till the end of operation in water with the surfactant. The surfactant incresed the nucleate boiling heat transfer and PEEK resin decreased one.