Poly Arylene Ether Research Articles

Surface segregation of rigid polyarylene ether amidoxime on polyurethane nanofiber into hierarchical membranes as substrate of flexible SERS nanosensor for sulfamethoxazole detection

Electrospun polymeric nanofibrous membranes are emerging as the promising substrates for preparation of flexible SERS nanosensors due to their intrinsic nanoscale surface roughness, easy scalability as well as rich surface reactivity. Although the nanofiber membranes prepared from high performance thermoplastics exhibit good mechanical stability, the SERS nanosensors based on these substrates normally have lower signal-to-noise ratio because of the interference from background Raman signals of aromatic moieties. Herein, we synthesized an optically transparent polyurethane (PU) and rigid polyarylene ether amidoxime (PEA), which were electrospun into core-shell nanofibers membranes with a “beads-on-web” morphology. Furthermore, the PU-PEA membranes were coated with ultra-thin silver layer and thermally annealed to prepare the flexible SERS nanosensor without any background noises. In addition, the Raman enhancement of SERS nanosensor can be readily improved by tuning of PU-PEA composition, silver thickness as well as thermal annealing temperature. Finally, the optimized SERS nanosensor enables label-free detection of sulfamethoxazole as low as 0.1 nM with a good reproducibility and detection performance in real water sample. Meanwhile, the optimized SERS nanosensor shows long term anti-biofouling capacity. Thanks to its facile fabrication, competitive analytical performance and resistance to biofouling, the current work basically open new way for design of flexible SERS nanosensors for biomedical applications.

Characteristics of in-situ automated fiber placement carbon-fiber-reinforced low-melt polyaryl ether ketone laminates part 1: Manufacturing influences

This study presents an investigation into mechanical and thermal properties, as well as the microstructure of Automated Fiber Placement-manufactured laminates using a novel carbon fiber-reinforced low-melt polyaryl ether ketone polymer material. The material’s lower melting temperature and lower melt viscosity as compared to established high-temperature thermoplastic materials as PEEK, promises favourable characteristics for the Automated Fiber Placement process. This work aims at in-situ consolidation and the influence of a heated tooling and a post process tempering step, which both turned out to be promising in previous investigations. Laminates were manufactured using a cold tooling, a heated tooling configuration, a cold tooling with a subsequent tempering process step and a hot-pressed reference laminate. Differential Scanning Calorimetry showed that crystallinity values more than doubled for the heated tooling and post process tempering configurations, compared to the cold tooling, reaching 24% and 30%, respectively. Mechanical strength values showed an increase in interlaminar shear strength and compression strength but did not increase to the same extent as was expected from the increase in crystallinity. With Scanning Electron Microscopy differences in the microscopic structure of the polymer matrix could be detected. While the post process tempering step leads to a mostly lamellar crystalline structure, the heated tooling configuration and the post process hot pressing induce a predominance of crystalline spherulites, which might positively affect the mechanical performance. Computed Tomography scans revealed a high amount of porosity in the in-situ-manufactured samples and unprocessed tape material, which likely mitigated the positive effect of increased crystallinity.

Biomimetic polyaryl ether-based aerogels for efficient interfacial solar water vapor generation

There is an urgent need to design efficient photothermal layer, continuous water migration pathways, and stable insulation layer to simultaneously achieve ideal water and heat management in solar-powered interfacial evaporation systems. Here, we assemble into a biomimetic aerogel with down-feather-like shape by first introducing rigid polyaryl ether material of sulphonated poly (phthalazinone ether sulfone ketone) (SPPESK) for highly efficient and multifunctional solar interfacial evaporation drawing inspiration from the cavity structure and insulation strategy of the eagle wings. The biomimetic aerogel has an evaporation rate of 2.34 kg m−2h−1 at one solar irradiance, an energy efficiency of 91.7 %, and an output voltage of 316.7 mV when coated. The insights provided by this work into biomimetic structure displayed by chitosan/SPPESK/Mxene aerogels promise to translate photothermal conversion performance benefits measured in laboratories into real-world applications for continuous desalination and wastewater purification. We anticipate that our work is a starting point to utilize the full potential of photothermal properties of polyaryl ether-based materials.

Polyaryl sulfone amine oxide membranes with adjustable pore and interesting “trade-off” effect

Creating advanced polymer membranes with adjustable pores for various separation methods has been challenging because of the lack of new materials with adaptable and reversible chemical structures. In this study, we designed membranes using polyarylene ether sulfone/amide tertiary amine (PAES/ATA) copolymerized with polyarylene ether sulfone and polyamide tertiary amine. These membranes incorporated amine oxide units into their molecular chains by oxidizing the TA unit in the PAES/ATA copolymer chain. Applying the oxidation process improved antifouling properties, with the oxidized membrane showing a permeance recovery rate (Frr) of 95.48 % and a total fouling ratio (Rt) of 9.35 %. These units also functioned as switches, altering their charge in different pH environments, thereby allowing pore size adjustment in the membranes. Notably, with the formation of amine oxide, these membranes exhibited properties distinct from the traditional “trade-off” effect, which is a persistent challenge in membrane technology development. The permeance and rejection rate of these membranes demonstrated the “simultaneous rise phenomenon” following a facile oxidation treatment to form amine oxide. This study presents a novel approach to develop membranes with new functional and tunable filtration capabilities, potentially applicable in various separation processes.

Protecting Orthopaedic Implants from Infection: Antimicrobial Peptide Mel4 Is Non-Toxic to Bone Cells and Reduces Bacterial Colonisation When Bound to Plasma Ion-Implanted 3D-Printed PAEK Polymers.

Even with the best infection control protocols in place, the risk of a hospital-acquired infection of the surface of an implanted device remains significant. A bacterial biofilm can form and has the potential to escape the host immune system and develop resistance to conventional antibiotics, ultimately causing the implant to fail, seriously impacting patient well-being. Here, we demonstrate a 4 log reduction in the infection rate by the common pathogen S. aureus of 3D-printed polyaryl ether ketone (PAEK) polymeric surfaces by covalently binding the antimicrobial peptide Mel4 to the surface using plasma immersion ion implantation (PIII) treatment. The surfaces with added texture created by 3D-printed processes such as fused deposition-modelled polyether ether ketone (PEEK) and selective laser-sintered polyether ketone (PEK) can be equally well protected as conventionally manufactured materials. Unbound Mel4 in solution at relevant concentrations is non-cytotoxic to osteoblastic cell line Saos-2. Mel4 in combination with PIII aids Saos-2 cells to attach to the surface, increasing the adhesion by 88% compared to untreated materials without Mel4. A reduction in mineralisation on the Mel4-containing surfaces relative to surfaces without peptide was found, attributed to the acellular portion of mineral deposition.

Design and synthesis of low‐dieclectric polyaryl ethers containing bulky tetraphenyl vinyl pendant group

AbstractA tetraphenylethylene‐containing bisphenol monomer 5‐[4‐(triphenylvinyl)phenyl]benzene‐1,3‐diol (TPE‐OH) was designed and synthesized by Suzuki coupling and nucleophilic substitution reaction. By adjusting the proportion of TPE‐OH, a series of rigid polyaryl ether, namely PPTES, were facilely synthesized by homopolymerization or copolymerization with 4‐(4‐hydroxyphenyl)‐2,3‐diazepine‐1‐one (DHPZ) and 4,4′‐difluorodiphenyl sulfone (DFS). The following characterization of their structures with nuclear magnetic resonance and infrared spectroscopy confirmed successful synthesis of both monomers and polymers. Large, volume‐twisted and non‐coplanar rigid tetraphenylethylene could effectively increase the molecular chain spacing and reduce the regularity of the molecular chain, as evidenced by molecular dynamics simulation with Materials Studio, in turn to form an amorphous nature of PPTES phase state. In addition, such PPTESs have excellent solubility, heat resistance, and other comprehensive properties. Their glass transition temperature (Tg) is between 219 and 300°C, and the 5% thermogravimetric temperature of PPTESs locates at 490–539°C under N2 atmosphere. At 1 GHz, the intrinsic dielectric permittivity of polymer films is between 2.32 and 2.61, gradually decreases with TPE‐OH content. This work would provide new idea and choice for the selection of polyaryl ether resin bisphenol monomer, and promote the development and application of low‐dielectric polyarylether materials.

Synthesis, characterization, and thermal pyrolysis mechanism of high temperature resistant phenolphthalein-based poly (arylene ether nitrile)

Phenolphthalein (PP) is usually used as a functional monomer to design novel high performance polymers with adjustable thermal, mechanical, and fluorescent properties. In this study, a soluble, amorphous, high temperature resistant PP-based poly (arylene ether nitrile) (PAEN) was synthesized and its corresponding thermal decomposition mechanism was reported via TGA/DTG, TGA/FTIR and TGA/MS analysis. PP-based PAEN showed a Tg of 250 °C a Tdmax of 503 °C and a char residue of 59.2 % at 800 °C, respectively. According to Kissinger and Flynn–Wall–Ozawa model, the activation energy of thermal pyrolysis was calculated as 225 ± 4 and 284 ± 17 kJ/mol respectively, higher than those of other poly arylene ethers. PP-based PAEN showed a three-stage thermal pyrolysis mechanism. Its initial degradation happened before 400 °C and liberated the inherent moisture. The latter backbone decomposition between 400 and 600 °C involved multiple routes mainly from the CO and CC cleavages of lactone ring, resulting in a Ph2CHPhOPh intermediate by releasing HCHO, HCOOH, CO2, H2O, CH4, C6H6, and C6H5OH. The third carbonization stage over 600 °C included the transformation from biphenyl linkages to aromatic graphite by dehydrogenation. This study not only gives a comprehensive understanding of the thermal pyrolysis behavior of PP-based PAEN, but also provides valuable references for the thermal behaviors of other PP-containing polymers.

Characteristics of in-situ automated fiber placement carbon-fiber-reinforced low-melt polyaryl ether ketone laminates part 2: Effect of prepreg composition

This paper presents an investigation into prepreg tape composition and its impact on the consolidation quality of in‐situ Automated Fiber Placement-manufactured laminates. Three different prepreg tape materials were investigated in terms of fiber distribution, porosity and surface roughness. Laminates were manufactured using the in-situ Automated Fiber Placement process and subsequently tested using microanalysis and mechanical testing methods. Higher quality prepreg tape material yielded lower porosity laminates and increased mechanical strength results. The best in-situ Automated Fiber Placement-manufactured laminates achieved 82 % and 88 % of hot-pressed reference tensile- and compressive strength, respectively. Prepreg tape with disadvantageous composition for in‐situ consolidation yielded up to 74 % knockdown compared to the best in-situ consolidated laminates. A five-point bending test was successfully used to determine interlaminar shear strength with significant results relating to consolidation quality. A correlation was successfully established between prepreg composition, resulting laminate consolidation quality and mechanical properties.

In-situ polymerization of PANI nanocone array on PEN nanofibrous membranes for solar-driven interfacial evaporation

Solar-driven interfacial evaporation (SDIE) holds great potential for desalination, but it also poses challenges to application performance. Herein, a novel polyaniline (PANI) modified polyarylene ether nitrile (PEN) electrospun nanofibrous membranes (PANI@PEN) was developed by introducing PDA and CTAB, which increased the polymerization amount of PANI and controlled its morphology by sequential in-situ polymerization, aiming to enhance its SDIE comprehensive performance. This unique structure can generate multiple diffuse reflections under sunlight, resulting in the highest water evaporation rate of the nanofibrous membrane at 1.822 kg m−2 h−1, while evaporation rate at 1.527 kg m−2 h−1 for a 3.5 wt% sodium chloride solution. Due to the good flexibility of PEN polymer substrate, the obtained membranes can be easily arched, showcasing an interesting ability to collect salt through salt deposition. Meanwhile, PEN also provides a robust skeleton, endowed PANI@PENs with corrosion-resistant, capable of desalination in acidic media, purifying heavy metal ion solutions through evaporation, as well as good mechanical properties for reusability. The study potentially provides a strategy for utilizing dopamine and CTAB loaded on high-performance polymer nanofibrous membranes and the convenient in-situ polymerization to generate advanced photothermal PANI. This strategy paves a way to enable high-performance engineering polymer, PEN, with solar-thermal evaporation capabilities, further opening its potential applications in seawater desalination and industrial wastewater purification.

ИССЛЕДОВАНИЕ ФИЗИКО-ХИМИЧЕСКИХ ОСОБЕННОСТЕЙ СТРОЕНИЯ И ЭЛЕКТРОННЫХ СВОЙСТВ СОПОЛИАРИЛЕНЭФИРКЕТОНОВ

In this work model compounds for copolymers of polyarylene ether ketones (co-PAEK) were modeled and analyzed, and optical and electrophysical studies were carried out. Quantum chemical calculations of the structures were carried out using the density functional theory (DFT) method in the B3LYP/6-31+G(d) approximation. The optical properties of the films were studied using the optical absorption method in the UV-visible region. The study of the current-voltage characteristics and time dependences was carried out on the MPI ETS50 probe station.

Core-shell structure polydopamine and polyethylenimine co-assisted MoS2-BaTiO3/polyarylene ether nitrile nanocomposites for high-temperature resistant organic dielectrics

In this work, a novel nanoparticle ((MoS2-BT)@(PDA+PEI)) was constructed through two-dimensional molybdenum disulfide (MoS2) and zero-dimensional barium titanate (BT) via in-situ polymerization and co-modification of polydopamine (PDA) and polyethylenimine (PEI). Then the nanofillers were dispersed in the Polyarylene ether nitrile (PEN) matrix by film casting to obtain PEN/(MoS2-BT)@(PDA+PEI) nanocomposite dielectric films. Subsequently, the latter were subjected to chemical crosslinking at high temperature to obtain CPEN/(MoS2-BT)@(PDA+PEI) nanocomposites. The effects of filler content on the properties of PEN matrix composite films were investigated. The results indicate excellent compatibility between (MoS2-BT)@(PDA+PEI) and the PEN matrix due to the introduction of an organic modification layer, resulting in overall good performance of nanocomposite films, including good thermal stability with a glass transition temperature (Tg) exceeding 240 °C after chemical crosslinking. The dielectric constant of CPEN nanocomposites containing 40wt% of the hybrid nanoparticles is 20.2 and the dielectric loss is 0.032 at 1kHz, the dielectric constant-temperature coefficient of all CPEN nanocomposites is less than 6×10-4 °C-1 at the temperature range of 25-220 °C. In short, the incorporation of (MoS2-BT)@(PDA+PEI) effectively enhances the thermal, mechanical, and dielectric properties of PEN-based nanocomposites.

Optimization and regulation of alcohol-based co-foaming agents on foaming behavior of ultra-low dielectric constant polyarylene ether nitrile foam in supercritical CO2

The incorporation of high porosity can effectively mitigate the dielectric constant and dielectric loss of polymers, thereby satisfying the stringent demands of ultra-low dielectric constant materials (ultra-low k < 2.0) in high-frequency and high-speed communication networks. In order to effectively enhance the foaming ability of the polyarylene ether nitrile (PEN), alcohol-based co-foaming agents with different chain lengths were introduced to fabricated high expansion ratio PEN foam using supercritical carbon dioxide foaming technology. By regulating and optimizing foaming temperature, type and content of co-foaming agents, the foaming window of PEN foam can be expanded by 20 °C while achieving a maximum expansion ratio (R) of up to 6.7. PEN foam achieves the preparation of materials with ultra-low k, with a minimum dielectric constant and dielectric loss of only 1.26 and 0.0025, respectively. The results obtained from fitting the theoretical model indicate that, for PEN foams with a porosity exceeding 80 % (R > 5.0), both the Bruggeman equation and the Clausius-Mossotti equation closely approximated the measured values. Additionally, PEN foam exhibits excellent thermal stability (Td5 > 445.8 °C) due to the "physical shielding" effect provided by cells. These advancements contribute to enhancing competitiveness of PEN foam with ultra-low k in for modern communication fields.

Multiscale insight to tribological mechanism of PTFE/aramid fiber composite liner containing PES/PMPS microcapsules under a high temperature environment

Polyaryl ether sulfone/polymethylphenlsiloxane (PES/PMPS) microcapsules were prepared and added to a polytetrafluoroethylene (PTFE)/aramid fiber composite liner for the first time to improve the tribological properties of self-lubricating fiber liners under high-temperature environments. Compared with the virgin liner, the friction coefficient and wear rate of the liner containing 9 wt% PES/PMPS microcapsules are reduced by 48.5% and 21.6%, respectively. At the microscopic and atomic scale, lubricant PMPS changes the interaction energy between PTFE and the Fe layer to weaken the adhesion of PTFE to the friction couple, further reducing the adhesive wear of the liner. Under the action of lubricating phases PMPS and PTFE, the tribological properties of the liner are significantly improved.

Synthesis and Properties of Semicrystalline Poly(ether nitrile ketone) Copolymers.

As a high-performance engineering plastic, polyarylene ether nitrile (PEN) is widely used in many fields. The presence of cyano groups of PEN ensures its good adhesion to other substrates, but the inherent low crystallinity of PEN limits its application. In this work, the poly(aryl ether ketone) segment was introduced into PEN via copolymerization using both 2,6-Dichlorobenzonitrile and 4,4'-Difluorobenzophenone as the starting reagents to prepare poly (ether nitrile ketone) (BP-PENK). The effect of composition and thermal treatment on the crystallization behavior and properties of poly (ether nitrile ketone) were systematically studied. It was found that when the content of DFBP is 30%, the copolymer BP-PENK30 had the best mechanical properties, with a tensile strength of 109.9 MPa and an elongation at a break value of 45.2%. After thermal treatment at 280 °C for 3 h, BP-PENK30 had the highest crystallinity with a melting point of 306.71 °C, a melting enthalpy of 5.02 J/g, and crystallinity of 11.83%. Moreover, with the increase in crystallinity, the dielectric constant and energy density increased after thermal treatment. Therefore, the introduction of poly(aryl ether ketone) chain segments and thermal treatment can effectively improve the crystallization and the comprehensive properties of PEN.

Removal of Monovalent and Divalent Cations from Brine Water by Electrodialysis Using Modified Polyethersulfone Membranes

In electrodialysis, an ion exchange membrane removes unwanted ions from wastewater and toxic metal ions from effluents. Montmorillonite-based modified "polyethersulfone membranes" have been studied as a potential small-scale electrodialysis approach for removing ions from wastewater. The study featured several steps, including solid polymerization, electrolyte balance, and removal of each component from the water. The study used three distinct “cation-exchange membranes (CEM)" types. The selected water body was diluted 100 times before being added to the electrodialysis cell in amounts of the center, cathodic, and anodic chambers, each containing 55, 30, and 40 mL. The initial pH for the real solutions of the water body was 7.16 at 25°C. Compared to "Sulfonated poly arylene ether sulfone (S-PESOS)" (23.23%) and Nafion® (35.34%), "hexamethylenediamine (HEXCl)" stands out as the only cross-linked material with significantly high-water content. When the membrane water content is too high, the membrane may lose its mechanical strength and cannot provide enough ionic conductivity. The semi-empirical model's parameters were estimated to simulate the elimination of Na+, K+, Ca2+, and Mg2+ by three membranes. HEXCl and S-PESOS were electrodialyzed and used to treat the serial dilution from the water with cationics. The removal rate gradually rose after the electrodialysis started.

Facile strategy for intrinsic low-κ dielectric polymers: molecular design based on space charge conservation.

The growing need for high-power and compact-size microelectronic integrated circuits (ICs) in modern microelectronic industries and 5G communication systems demands low dielectric constant (κ) polymer dielectrics with excellent temperature capability, mechanical property and processability. However, conventional molecular design strategies often face difficulties of a trade-off between optimizing the dielectric performance of polymers and maintaining the aforementioned properties. Herein, we present an innovative and facile strategy that utilizes the space charge distribution characteristics of the target co-monomer to solve this trade-off. Based on this design strategy, a novel polyaryl ether ketone (PAEK) with two different charge distribution units (BAF and SBI) was designed and synthesized. Both the experimental results and computational simulations confirm that these two components serve to weaken the polarization of molecular chains in the electric field, induce higher molecular chain packing density and fewer weaknesses, and synchronously regulate the κ, dielectric loss (tan δ), thermal and mechanical properties and processability by generating a strong inter-chain electrostatic interaction. The resultant copolymer, PAEK-4F6S, exhibits exceptional low κ and tan δ values of 1.98 and 0.0024 at 1 MHz, respectively, and these values remain stable over a broad frequency (1-106 Hz, 8.2-12.4 GHz) and temperature range (30-150 °C). Furthermore, the resultant copolymer demonstrates excellent thermal stability and mechanical properties, with a glass transition temperature (Tg) of 195 °C, 5 wt% decomposition temperature (Td5%) of 498 °C under N2, tensile strength of 63.5 MPa and tensile modulus of 1011.2 MPa, respectively. The synthesis procedure of these resultant copolymers is facile, and they are found to have favorable solution and melt processing properties, making them suitable for processing and scalable production. More importantly, this design strategy is beneficial for lowering the κ and tan δ values, and simultaneously enhancing the comprehensive performances of the objective polymers, which provides a completely novel and facile approach for the design and fabrication of high performance low-κ polymers suitable for the needs of microelectronics and communication fields.

Lightweight and high-strength polyarylene ether nitrile-based composites for efficient electromagnetic interference shielding

Abstract The proliferation of electronic devices and the widespread adoption of microwave-based technologies have resulted in a notable rise in electromagnetic radiation pollution. In present work, a novel flexible lightweight polyarylene ether nitrile (PEN)-based composite for efficient electromagnetic interference (EMI) shielding was prepared by introducing dual-loss hybrid material (PKMWCNT@Fe3O4) into PEN via non-solvent induce phase separation method and assembling it layer-by-layer with carbon fiber (CF) fabric. The porous morphology of the PEN layer, the electrical conductivity of the CF fabric, and the dual-loss property of the filler enable the material to reflect and absorb electromagnetic waves multiple times, resulting in superior electromagnetic shielding performance. With the addition of PKMWCNT@Fe3O4 at a mass fraction of 50%, the EMI SE T and specific shielding effectiveness SSE/t can reach up to 47.08 dB and 617 dB cm2/g, respectively, indicating absorption dominated shielding mechanism. Furthermore, the material exhibits a lightweight nature with a density of 0.55 g/cm3, and excellent mechanical properties, including a tensile strength of 43.98 MPa and elongation at break of 43.32%. This work presents a new approach to prepare high-performance composites that are both lightweight and resistant to secondary contamination by electromagnetic waves.

Semi-fluorinated (6F) polyaryl ethers and polyphenylenes via interfacial electrophilic condensation polymerization with hexafluoroacetone hydrate

A series of semi-fluorinated polymers were obtained by Friedel-Crafts polymerization of hexafluoroacetone trihydrate (HFAH) with a variety of activated and non-activated aromatic monomers. Interfacial (water/dichloroethane) electrophilic aromatic substitution (EAS) polymerizations were carried out with trifluoromethanesulfonic anhydride (Tf2O) and Aliquat® 336 as phase transfer catalyst. This versatile and straightforward method achieved the synthesis of moderate to high molecular weight (12.0–29.6 kDa) polyaryl ethers and polyphenylenes with 1,1,1,3,3,3-hexafluoroisopropylene (6F) main chain linkages. Predominantly amorphous film-forming materials were obtained with low branching, high solubilities in common organic solvents, thermo-oxidative stabilities up to 500 °C, and glass transitions (Tg) ranging from 157 to 250 °C. The optical and dielectric properties of these materials were also studied from which high visible region transmittance and low dielectric constant values comparable with commercial materials were found.

Substantial improvement of thermal conductivity and mechanical properties of polymer composites by incorporation of boron nitride nanosheets and modulation of thermal curing reaction

AbstractThermal conductive polymer‐based composites synchronously with stable dielectric and excellent mechanical properties are urgently needed for high‐temperature‐resistant electronic devices. Here, a significant improvement in the thermal conductivity (TC), thermal stability, dielectric, and mechanical performance was simultaneously achieved in the polyarylene ether nitrile (PEN)/divinyl siloxane‐bisbenzocyclobutene (BCB) matrix through the incorporation of boron nitride nanosheets (BNNS) combined together with the post‐solid phase chemical reaction technique. The significant increase in the effective filler‐filler and filler‐crystal contacts in the composites was the main reason for the improvement in TC and dielectric constant. Besides, glass transition temperature (Tg) and mechanicals were enhanced in the presence of cross‐linked networks. By synchronously adding 15 vol% BNNS, the TC of composites after treatment reached up to 5.582 W/m.K, enhanced by 4.4 times higher than untreated. The dielectric constant was down to 2.93 at 1 MHz and the loss remained at a relatively low level. Meanwhile, the composite showed significantly enhanced thermal stability, mechanicals, and hydrophobicity (Tg = 336°C, T5% = 529°C, tensile strength and modulus was 94.5 MPa and 5.3 GPa, respectively, the contact angle was 101.76°). Thus, it promotes an effective strategy for fabricating a high‐performance‐polymer composite, which has the potential used in electronic materials.Highlights Crystallization‐crosslinking strategy optimizes overall performance. Crystals fill gaps between BNNS layers and connect thermal conductive pathway. Crosslinked networks limit molecular chain motion to reduce phonon scattering. The highest TC of the PEN/BCB/BNNS composite is up to 7.451 W/m.K. Thermal property shows significant improvement after crosslinking especially Tg.

Enhancing interfacial adhesion of carbon fiber/poly(phthalazinone ether ketone) composites by the hybrid sizing agent of hydroxyapatite‐reinforced PAEK‐COOH

AbstractImproving the interfacial adhesion of carbon fiber (CF)/polymer composite is an urgent demand to enhance its mechanical properties. A kind of poly(aryl ether ketone) with carboxyl groups (PAEK‐COOH) was newly synthesized. PAEK‐COOH is similar to the thermal properties of PPEK matrix. Hydroxyapatite (HAp) was easily dispersed in an NMP solution containing PAEK‐COOH. Different kinds of hybrid sizing agents were obtained for preparing the prepreg through the solution impregnation. The hot‐pressing method was employed to produce the laminated composites. Flexural strength, flexural modulus and interlamellar shear strength (ILSS) of 0HP@CF/PPEK composites were improved by 8.8%, 17.3%, and 14.7%, respectively, in comparison to desized CF/PPEK. The interface bonding between CF and PPEK was improved by the addition of PAEK‐COOH sizing agent. Meanwhile, compared with desized CF/PPEK laminates, flexural strength, flexural modulus and ILSS of 5HP@CF/PPEK composites were enhanced by 63.5%, 87.4%, and 40.9%, respectively. The crack propagation path became dispersed and the stress was effectively absorbed when the sizing agent containing nano‐hydroxyapatite particles. By characterizing and reconstructing the transverse and longitudinal fracture in composite materials, the failure process of the composites under the action of stress was explained, and the interface theories of CF reinforced polymer were further explored.Highlights A kind of polyaryl ether ketone containing carboxyl functional group (PAEK‐COOH)was newly synthesized. HAp was distributed in the polymer sizing agent to obtain a HAp/PAEK‐COOH hybrid sizing agent. The interfacial adhesion of CF/PPEK composite was greatly improved by the hybrid sizing agent.