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N1-alkyl (octyl and dodecyl)-substituted imidazolium-based PVBC homopolymers have been synthesized via N-quaternization reaction of N1-alkyl imidazole and PVBC precursor homopolymer bearing reactive benzyl chloride moieties. Due to their poor film forming properties and water solubility, these homopolymers were blended with aromatic polyethers bearing main chain pyridine units at different compositions in order to study the effect of alkyl chain length on morphology, water uptake, swelling ability and chemical stability of the prepared membranes. The B2 blend membrane with the highest N1-dodecyl-substituted imidazolium PVBC content (65 wt%) exhibited the highest water uptake (54%) despite its lower IEC value compared to the corresponding one containing N1-octyl-substituted imidazolium PVBC, low swelling ratio and a phase separated morphology. Evaluation of the chemical stability in 3.6 M KOH solution at 80 °C for 7 days revealed the degradation of imidazolium via ring opening, as evidenced by ATR-FT-IR spectroscopy. Therefore, new blends having as second constituent, the N1-alkyl-substituted imidazolium functionalized poly(PVBC-co-AA20) copolymers containing acrylic acid units were fabricated targeting to the improvement of chemical stability via ionic cross linking. The prepared D1 and D2 blend membranes containing 60 and 65 wt% dodecyl-imidazolium functionalized poly(PVBC-co-AA20) copolymer content, respectively, were flexible, exhibited moderate IECs (1.47–1.60 meq/g) and sufficient water uptakes (up to 30%). D2 blend membrane showed excellent chemical stability after testing in 3.6 M KOH solution at 80 °C for 30 days, as confirmed by ATR-FT-IR spectroscopy and TGA analysis. The excellent chemical stability can probably be attributed to the steric hindrance effect of N1 dodecyl substituent which effectively protects the C2 position of imidazolium from hydroxide attack as well as to the formation of a dense, ionic cross-linked structure that hinders hydroxide penetration. [ABSTRACT FROM AUTHOR]

The synthesis of heat-resistant thermoplastic polymers from the class of aromatic polyethers, namely, cardo poly(arylene ether ketones) (co-PAEK) and cardo poly(arylene ether sulfones) (co-PAES) with different content of phthalide or fluorene moieties and variable molecular weight has been carried out. Thermomechanical, adhesive, optical, and electrical properties of copolymers were studied with the aim of using co-PAEK and co-PAES in the current collecting system of solar cells for the formation of an electrical contact metal/polymer/transparent conducting oxide. These properties were investigated in dependence on the content of cardo groups in the macromolecule, as well as on polymer molecular weight. [ABSTRACT FROM AUTHOR]

Aimed to optimize the ratio accuracy/computational cost, in this work we study the performance of three different theoretical methodologies in the calculation of the optical bandgap for a test set made of a number of poly(aryl-ethynylene)s related polymers. Infinite, ideal polymer chains were first optimized by means of periodic calculations. Different length oligomers were afterward generated by direct replication of the corresponding periodic structure and their optical bandgaps were calculated by means of different time dependent-density functional theory (TD-DFT) methodologies. These results were fitted to an exponential function for each oligomer family in order to get a theoretical estimation of the optical bandgap for each polymer to be compared to the experimental reported values. The best result was obtained for TD-M06-2X yielding an average deviation of 3.4% with respect to the experimental values. [ABSTRACT FROM AUTHOR]

A low dielectric constant polyarylether (PAE) polymer was investigated for resistance to copper drift. Positive bias-temperature stressing (BTS) of metal/PAE/SiO[sub 2]/Si capacitors led to large initial flat-band voltage shifts toward the left-hand side in the capacitance–voltage curve for all gate metals investigated (Pt, Al, and Cu). Upon triangular voltage sweep (TVS) testing, Pt/PAE/SiO[sub 2]/Si capacitors exhibited no peak, whereas a single peak (indicative of mobile ions) was seen for Cu/PAE/SiO[sub 2]/Si capacitors. The results indicate that an intrinsic polymer instability source, such as polarization (under bias), was the major cause for the BTS instability of the polymer. From TVS studies, Cu[sup +] ion drift could be characterized in the temperature range of 150–250 °C, and mobility of Cu[sup +] in PAE was extracted from Hillen’s analysis. A combination of BTS and TVS techniques is thus more useful for characterization of copper drift, and helps to resolve the intrinsic polymer effect from that of metal drift-related instability. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

2,7-Bis(4-fluorobenzoyl)fluorene reacted with 4,4-oxybiphenol to give 2,7-fluorenediyl-containing poly(ether ketone), which is insoluble in CHCl3 and DMSO. On the other hand, 9,9-dihexyl/diethyl-2,7-bis(4-fluorobenzoyl)fluorenes reacted with 4,4-oxybiphenol to give the desired poly(ether ketone)s, which are soluble in typical organic solvents. Furthermore, polymerization of 9,9-diethyl-2,7-bis(4-fluorobenzoyl)fluorene with several aromatic diols afforded the corresponding aromatic poly(ether ketone)s. Almost all the resulting poly(ether ketone)s have good organosolubility, thermal stability (Tg = 120-199 °C), and blue-green or green-emitting properties. [ABSTRACT FROM AUTHOR]

Anion exchange membranes with star main chains or side chains were prepared by grafting the 1-butyl-2-methylimidazole and/or 1-aminopropyl-2-methyl-3-butylimidazolium hydroxide onto branched or linear poly(aryl ether ketone) polymers. In order to know the influence of the star structures on the physicochemical properties of the prepared membranes, comprehensive characterizations were made including ion exchange capacity, conductivity, mechanical property and alkaline stability. All the membranes exhibit conductivities of about 40 mS cm −1 at 60 °C and about 60 mS cm −1 at 80 °C, respectively. The durability of the membranes in alkaline medium was detected by monitoring the changes in conductivity, ion exchange capacity and contact angle with water. The results indicate that the introduced star structures of both main chains and side chains are effective to enhance the tensile strength and alkaline stability of the membranes. The membranes with star main chains exhibited a tensile stress at break of 45 MPa and retained a conductivity of 36.1 mS cm −1 at 60 °C after exposed to 1 M KOH at 80 °C for 300 h. [ABSTRACT FROM AUTHOR]

Aromatic ionomers have emerged as promising alternatives to perfluorosulfonic acid polymers to be applied as proton exchange membranes in fuel cells. However, the paradox between the ion conductivity and stability is still a challenge precluding the commercialization of aromatic ionomers. In this paper, we report the design of a novel sulfonated poly(arylene ether nitrile) multi-block structure by introducing a key component, alkyl benzotriazole (Bt) side chains, into the hydrophobic segments. The modified structure could facilitate polymer phase-separation and generate self-standing films with excellent mechanical properties, and it effectively suppresses the excessive swelling of the membrane owing to strong electrostatic interactions between the Bt chains and sulfonic acid groups. Moreover, the Bt unit could act as both a proton acceptor and proton donor, causing a dramatic increase in the ion conductivity of the membrane. The most optimal membrane possesses an ion-exchange capacity of 2.15 meq g −1 and exhibits a weaker relative humidity (RH) dependence and higher proton conductivity than the commercial Nafion 212 over the entire RH range. Remarkably, the maximum power output of the fuel cell based on the most optimal membrane reaches 1090, 856, and 451 mW cm −2 at 95%, 70%, and 30% RH, respectively, which are more than 2 times higher than those of the non-Bt analogue. Further, the current densities ( I 0.6 ) ranging up to 1500 and 1000 mA cm −2 (0.6 V) at 95% and 70% RH are both much higher than those of the Nafion. Our study provides a novel methodology for the design of aromatic ionomer structures with excellent performances for practical fuel cell application. [ABSTRACT FROM AUTHOR]

Two novel series of poly(aryl ether ketone)s (PAEK) bearing pendant carboxylic acid groups have been synthesized, and subsequently sulfonated to obtain sulfonated poly(aryl ether ketone)s with carboxylic acid groups (SPAEK-COOH- x ). The expected structures of the sulfonated copolymers were confirmed by FTIR. Modified nanocrystalline cellulose (NCC) was prepared and introduced into the SPAEK-COOH- x as the “performance-enhancing” filler and crosslinking agent. The nanocomposite proton exchange membranes were prepared via a solution-casting procedure. The composite membranes containing NCC presented the higher proton conductivity and better mechanical properties. After further crosslinking, the covalent crosslinked composite membranes showed even better mechanical properties while the proton conductivity and thermal stability were maintained. The hydrophilic/hydrophobic domains were observed from the TEM morphology investigation of COOH-10/NCC- y and C/COOH-10/NCC- y membranes. A balance of mechanical stabilities, proton conductivity, and thermal property could be designed by the incorporation of NCC and the crosslinking between NCC and SPAEK-COOH-10 to meet the requirements for the applications in the fuel cells. [ABSTRACT FROM AUTHOR]

The development of a suitable polymeric bioactive composite with hydroxyapatite as a filler is one of the very actively pursued areas in bioapplications. This report concerns development of such a novel polymeric biocomposite viz. poly (aryl ether) ketone-poly (dimethylsiloxane) with a small percentage of nano carbon fibres and varying percentages of nanohydroxyapatite particulates as fillers. The earlier characterization of this material involving mechanical, thermal and bio-compatibility studies showed optimum improved behaviour at about 7% nanohydroxyapatite loading as reported elsewhere. In this study, the wear and friction response of this biocomposite was tested in air under dry sliding conditions against hard steel using a pin-on-disc apparatus. Interestingly, the adhesive wear characteristics of this nanocomposite with varying nanohydroxyapatite percentages showed a trend similar to that in other characteristics with lowest wear occurring around the same nanohydroxyapatite percentage. It was observed that the specific wear rate in this novel nanocomposite was exceptionally low [~ 10 −8 (mm 3 /N-m)] compared to that in other similar polymer composites. The origin of this very low wear rate can be associated with the multiple strategies used in the preparation of this nanocomposite such as the use of poly (dimethylsiloxane) which is known to provide a cushioning effect in the matrix. In addition, the phosphate grafting of poly (dimethylsiloxane), the nanonature of both the fillers and their specific surface treatments using aminosilane for enhancing the matrix- filler interfacial bonding all of them seem to have played their expected beneficial roles resulting in the above very low wear rate. The earlier studies on this nanocomposite have shown improvement of the mechanical compressive strength with the addition of carbon nanofibres. Interestingly, here the friction coefficient of the nanocomposite with carbon nanofibres is consistently higher than that without carbon nano fibres for different nanohydroxyapatite percentages samples, for both low (5 N) as well as high (30 N) applied load. It could possibly be due to dislodged carbon nano fibres acting as a third body abrasive or fibres acting as weak links in the matrix filler network affecting the friction response. These wear and friction measurements have clearly brought out the various interesting aspects of the tribological response of the nanocomposite material and the intricate roles played by its matrix component poly (dimethylsiloxane) and the surface treated nano fillers nanohydroxyapatite and nano carbon fibre. [ABSTRACT FROM AUTHOR]

Core-shell structured PbZrO3@BaTiO3 nanoparticles (PZ@BT) were prepared through a modified hydrothermal method and characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), x-ray photoelectron spectroscopy (XPS) and x-ray diffraction (XRD). The SEM, TEM images and TEM energy dispersive spectrometer mapping demonstrate that the PZ shell successfully forms on the BT core and the thickness of the PZ shell is approximate at 20 nm. The XRD pattern demonstrates the characteristic diffraction of the PZ shell, and the XPS result also indicates the presence of lead and zirconium, which confirm the fabrication of PZ@BT. Afterwards, the PZ@BT and polyarylene ether nitrile nanocomposites (PZ@BT/PENs) were prepared, and the mechanical, thermal, and their dielectric properties were systematically investigated. With the presence of PZ@BT, the glass transition temperature of the composites is enhanced while their thermal resistance is reduced. The composites show excellent tensile strength even 50 wt.% of PZ@BT is used. After the addition of PZ@BT, the permittivity of the composites is effectively improved. Dielectric loss of the composites shows a slight decrease when the content of PZ@BT increases. Furthermore, the composite with 5 wt.% of PZ@BT shows a breakdown strength of 215 kV/mm. [ABSTRACT FROM AUTHOR]

ABSTRACT: A series of phthalonitrile terminated polyaryl ether nitrile oligomers containing fluorene group (BPPENs) were synthesized and cured in the presence of bis[4‐(4‐aminophenoxy)phenyl]sulfone. Additionally, the quartz fiber reinforced composites were prepared by hot‐pressing process. The structure of oligomers was characterized by 1H‐NMR and GPC. The curing behavior of BPPENs was studied by DSC, IR, and rheological tests in detail. Thermal stability and mechanical properties were also investigated. The results showed that the oligomers showed excellent solubility. BPPENs could be dissolved in common solvents at ambient temperature. TGA and DMA results showed that the cured polymer and composites possessed excellent thermal properties with high residual weight of 72.4% at 1000 °C and 5% thermal degradation temperature (T5%) of 548 °C under inert atmosphere. The bending strength of quartz fiber reinforced composites was about 500 MPa, exhibiting good mechanical property. The products could be used as high performance polymers or a modifier for heat‐resistant resins. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46606. [ABSTRACT FROM AUTHOR]

To achieve high-performance thermosets from renewable resources, six acetovanillone-derived poly(aryl ether)s (two with the acetic moiety, two with the phenyl methacrylic moiety, and two with the vinyl benzyl ether moiety) were prepared. The poly(aryl ether)s with acetic- or phenyl methacrylic moiety were applied as epoxy curing agents to cure with a phenol-dicyclopentadiene epoxy resin (HP7200). The T g values of the resulting epoxy thermosets range from 228 to 252 °C (DMA data) and the dielectric constants range from 2.78 to 3.01 U (at 3 GHz). The two poly(aryl ether)s with vinyl benzyl ether moiety were self-cured to high-performance thermosets with T g values of 255 and 293 °C (DMA data) and with a dielectric constant of 2.89 and 2.68 U (at 3 GHz), respectively. This work successfully demonstrates a strategy to achieve high-performance thermosets from reactive polyethers, which are derived from renewable acetovanillone. [ABSTRACT FROM AUTHOR]

Superplasticizers are important additives used in concrete barriers in geological waste repositories. Superplasticizers have been a major concern in the long-term assessments of safe geological disposal for radioactive waste since superplasticizers and their degradation products can act as complexing ligands and thereby increase the mobility of radionuclides. In this work a new type of superplasticizer, based on a polyaryl ether polymer, has been characterized. It was found that the superplasticizer combines the structural features of polycarboxylate ether based superplasticizers and sulfonated naphthalene-formaldehyde based superplasticizers and that it contains organophosphate charged groups. A novel method for evaluating the rate of degradation of the superplasticizer under alkaline conditions was elaborated and the degradation products and rate constant of the process was determined. The results demonstrate that degradation occurs rapidly compared to the typical lifetime of a repository. [ABSTRACT FROM AUTHOR]

Novel poly(aryl ether sulfone ketone)s (PAESK) were synthesized from bisphenol A (BPA), 9,9′-bis(4-hydroxyphenyl) fluorene (BHPF), 4,4′-dichlorodiphenylsulfone (DCS) and 4,4′-difluorobenzophenone (DFB) via nucleophilic substitution polymerization, which were subsequently used to fabricate ultrafiltration membrane by phase-inversion method for high temperature condensed water treatment. The obtained high molecular weight co-polymers with fluorene group with good solubility and good thermal stability, can be easily cast into flexible, white and non-transparent flat films. The influence of molar ratio of BPA and BHPF on the properties of the prepared co-polymers and membranes was investigated in detail. SEM study of the morphology of the membranes indicated that the prepared membranes possessed homogeneous pores on the top surface and were sponge-like or finger-like in cross-section. Pure water flux of the membranes increased from 71.87 L·m−2·h−1 to 247.65 L·m−2·h−1, while the retention of BSA decreased slightly, and the water contact angle decreased from 82.1° to 55.6° with the PVP concentration from 0 wt% to 10 wt%. With increasing concentration of PVP, the mechanical properties of membranes decreased, while the thermal stability increased. The permeate flux measurement showed that the PAESK membrane had the potential for high temperature condensed water treatment. [ABSTRACT FROM AUTHOR]

Here, we use polyimide ( PI ), polyether ( PE ) and polyester ( PET ) with diphenyl sulfonyl ( S ) moieties combined with triphenylamine ( TPA ) units to obtain three polymer electrets, TPA-PIS , TPA-PES , and TPA-PETS , respectively. The pentacene-based organic field effect transistor (OFET) memories with the charge-trapping polymer electrets layer were examined. The variation in linkages in the polymer backbone noticeably influences the energy structures and molecular polarity, and thus their memory properties were systematically characterized and compared. Volatile memory characteristics can be observed for all three polymer electrets-based memories. Among these, the TPA-PIS and TPA-PETS electret OFET memory devices exhibit ambipolar trapping behavior capable of storing holes and electrons, with a memory window ( MW ) of 32.4 ± 1.2 V and 21.7 ± 1.0 V, respectively, and a memory ratio of 10 4 ∼10 6 . Importantly, programming/erasing switching endurance for at least 100 cycles is achieved, allowing for tri-state memory storage. However, hole-only unipolar trapping of OFETs memory with the TPA-PES electret presents relatively slower charge detrapping phenomena and longer retention time ability due to the higher molecular dipole moment. Our comparative study demonstrates the important role of the linkage effect in aromatic polymers for developing polymer electret-based OFET memories. [ABSTRACT FROM AUTHOR]

Weak osteointegration affects the long-term stability of polyaryletherketone (PAEK) implants. Surface modification provides a potential solution to improve the osteointegration property of PAEKs. Polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) are two representative PAEK materials, but the latter has more ketone groups and better potential for surface chemical modification than the former. In this work, porous PEKK (PEKK-P) and PEEK (PEEK-P) were fabricated by a porogen leaching method. The samples were treated with 80% sulfuric acid (PEKK-SP and PEEK-SP) and then simulated body fluid (SBF) incubation (PEKK-BSP and PEEK-BSP). More micropores and higher hydrophilic SO 3 H groups were found on PEKK-SP than PEEK-SP. Likely, more bone-like apatite crystals deposited on PEKK-BSP than PEEK-BSP. To evaluate their osteointegration properties, the samples were implanted in femoral condyle defects (Φ3 × 4 mm 3 ) of rat models, and micro-computed tomography (μ-CT), histology and mechanical analyzes were performed on the retrieved specimens. For control groups, i.e. the dense samples (PEKK-D and PEEK-D), only a handful of bone creeping growth on the implant surface was seen on them. However, with the interconnected macropores, surface micro/nano topography and bone-like apatite, notable bone growth into the inner pores was observed on PEKK-BSP and PEEK-BSP. Furthermore, quantitative analyses confirmed that the newly formed bone in PEKK-BSP was nearly more than doubled than that in PEEK-BSP. The push-out force testing results (PEKK-D ≈ PEEK-D < PEKK-P ≈ PEEK-P < PEEK-BSP < PEKK-BSP) suggested that the surface chemical modification (sulfonation treatment followed by SBF incubation) along with build-in porous structure played more important role in enhancing the mechanical stability of both PAEK materials than just the physical structure change. Our results revealed that PEKK with more ketone groups allowed easier sulfonation and better bone-like apatite deposition than PEEK, thus endowing PEKK-BSP with better osteointegration and mechanical stability than PEEK-BSP. Therefore, surface modified PEKK could be potential candidate for spinal and orthopedic applications requiring good osteointegration property. [ABSTRACT FROM AUTHOR]

Abstract: Poly(aryl ether sulfone ketone) containing phthalazinone and biphenyl moieties (PPBESK) is a promising candidate for replacing metal bone implants. Apatite synthesized by polydopamine‐assisted hydroxyapatite formation (pHAF) is a promising coating for bone‐implant application. In this study, a modified pHAF technique is employed to induce the formation of apatite onto PPBESK while phosphonate groups, as potent inducers of apatite formation, are introduced through modification of a polydopamine (PDA) layer. The PPBESK layer and surface‐modified samples are evaluated by Raman spectroscopy, contact angle measurement, scanning electron microscope (SEM), and X‐ray photoelectron spectroscopy, respectively. The surface roughness of the samples increases following self‐polymerization of dopamine and decreases after reacting with POCl3. PPBESK water contact angle reduces significantly after coating with PDA. Microstructural and compositional analyses by SEM and X‐ray diffraction reveal that apatite coating induced by phosphonate groups exhibits a greater quantity of apatite formation, a higher ratio of Ca/P than that induced by a pristine PDA layer. The surfaces are characterized by culturing with MC3T3‐E1 preosteoblasts. Apatite induced by phosphonate group conjugated to PDA layer on PPBESK surface promotes cytocompatibility and osteogenesis of MC3T3‐E1 preosteoblasts in vitro. [ABSTRACT FROM AUTHOR]

A series composited membranes of sulfonated poly(arylene ether sulfone) and graphene oxide (SPAES-GO-x) have been exploited as proton exchange membrane. The properties of SPAES-GO-x membranes were evaluated including proton conductivity, water uptake, swelling ratio, oxide and thermal stability. Incorporating GO into SPAES matrix restrained the composite membranes swelling and enhanced their proton conductivity. The SPAES-GO-3% membrane showed a conductivity value of 0.183 S cm −1 at 120 °C and relative humidity 100%. Compared with the pristine SPAES membrane, the swelling ratio of SPAES-GO-2% membrane was reduced by 55.7% at 90 °C. Small-Angle X-ray Scattering (SAXS) revealed GO promoted SPAES molecular chain movement to form bigger ionic clusters in favor of enhancing proton transport. X-Ray Diffraction and Field Emission Scanning Electron Microscope (XRD and FE-SEM) analysis further demonstrated GO was exfoliated and distributed throughout the SPAES matrix. These results indicated GO was an effective filler to trade off proton conductivity and swelling of composite membrane. [ABSTRACT FROM AUTHOR]

A series of fluorinated poly(aryl ethers) containing benzyltrimethyl quaternary ammonium functionalized fluorene units (QPFAE) are synthesized via condensation polymerization, chloromethylation, and quaternization. Ionomer structure and the ion exchange capacity are confirmed by 1H‐nuclear magnetic resonance spectroscopy. Other characterization techniques such as Fourier transform infrared spectroscopy, atomic force microscopy, thermogravimetric analysis, gel permeation chromatography, electrochemical impedance spectroscopy, Fenton, water‐swelling, and hydrolytic aging tests are used to evaluate the physicochemical properties of the as‐prepared QPFAE membranes. For the QPFAE membranes with ion exchange capacity of 0.95–1.94 mmol/g, they displayed low water uptake and methanol permeability (4.59–26.1 × 10−8 cm2/s at 25 °C), fairly good dimensional stability, high mechanical toughness, as well as fine thermal‐oxidative‐hydrolytic stability and ion conductivity at least 10 mS/cm. The membranes also showed clear hydrophilic/hydrophobic phase‐separation morphology. Furthermore, the QPFAE membranes could endure harsh basic conditions (1–4 mol/L NaOH solution) at 60 and 80 °C at least 240 h, keeping rather high mechanical toughness and ion conduction capability during the aging test. [ABSTRACT FROM AUTHOR]

The thermal conductivity of polyarylene ether nitrile (PEN) is effectively improved by the incorporation of boron nitride nanosheet (BNNS). BNNS is obtained via sonication exfoliation of commercial available hexagonal boron nitride (h‐BN) microplatelets in N‐methylpyrrolidone solvent. The BNNS, which is in 1–3 layers, is characterized by Atomic Force Microscopy measurement, Transmission electron microscopy observation and Ultraviolet–visible (UV–Vis) spectrum. The BNNS is incorporated into the PEN matrix to fabricate BNNS/PEN nanocomposites by using the solution‐casting method. The micromorphologies, thermal, mechanical, dielectric, and thermal conductivity properties of the obtained BNNS/PEN nanocomposites are investigated in detail. Scanning electron microscopy observation shows that the BNNS is homogeneously dispersed in the PEN matrix. The obtained BNNS/PEN nanocomposites show good thermal stability as the glass transition temperatures and initial decomposition temperatures of them are higher than 200 and 490°C. The coefficients of thermal expansion decreases with the increasing of BNNS, and is as low as 0.33 µm/°C when 5.0 wt% of BNNS is incorporated. The thermal conductivity increases with 64% at 5.0 wt% content of BNNS. The incorporation of the BNNS makes these BNNS/PEN composites as potential candidates to be used at high temperature with small thermal deformation. POLYM. COMPOS., 39:E1598–E1605, 2018. © 2017 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

A new class of poly(arylene ether nitrile) with a bisulfonated phenyl ring on the side chains (PAEN-bS) was prepared from a hydroxybenyl-containing polymer precursor and a bisulfonated monomer by applying graft reaction. The polymers were soluble in common organic solvents such as dimethylsulfoxide (DMSO, purity>99.5%; Sinopharm Chemical Reagent Co., Ltd, Shanghai, China), N,N-dimethylacetamide (DMAc, purity>99.0%; Sinopharm Chemical Reagent Co., Ltd, Shanghai, China), dimethylformamide (DMF, purity>99.0%; Sinopharm Chemical Reagent Co., Ltd), and 1-methyl-2-pyrrolidinone (NMP, purity>99.0%; Sinopharm Chemical Reagent Co., Ltd) and showed good thermal stability, with a 5% weight loss and temperature higher than 320°C. Remarkably, all the PAEN-bS membranes showed a high proton conductivity of more than 10−2 S cm−1 at room temperature and a low swelling ratio of less than 20% at 100°C; in particular, the conductivity of the PAEN-Bs-60 polymer membrane with the highest ion exchange capacity value was higher than that of Nafion 117 at all test temperature ranges. The combination of good thermal stability, excellent dimensional stability, and high proton conductivity indicates that these polymers are good candidate materials for proton exchange membranes in fuel cell applications. [ABSTRACT FROM AUTHOR]

ABSTRACT: Effectively dispersing of carbon nanotubes (CNTs) is the key to producing high performance CNTs/poly(aryl ethers) (PAEs) composite materials. Here, a series of novel soluble carbazole‐based PAEs with different alkyl side‐chains were synthesized corresponding polymers P1, P2, P3, and P4, and characterized clearly by 1H NMR and IR. All the polymers exhibited good mechanical properties and thermostabilities (Tg ∼ 128–212 °C, Td5% ∼ 450–499 °C) as PAEs. Due to containing lots of large π‐conjugated carbazole derivative units and possess suitable solubility, these non‐conjugated polymers can wrap and disperse MWNTs well (238–416 mg/L) in CHCl3, and the similar work has been reported rarely. This excellent property makes these polymers become a promising and ideal type solubilizer for CNTs/PAEs composite. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 46250. [ABSTRACT FROM AUTHOR]

Luminescent facial tris -cyclometallated iridium complexes of generic structure Ir(L) 2 (dbppy) with one 2-(4-bromophenyl)-5-bromopyridyl (dbppy) ligand {where L represents the cyclometallating ligands [2-phenylpyridyl (ppy), 2-(4,6- difluorophenyl)pyridyl] (dfppy), [1-phenylpyrazole] (ppz) or [1-(4,6-difluorophenyl)pyrazole] (dfppz)} were synthesized. The bromine substituents allow the further incorporation of the iridium complexes into a polyaryl backbone. The route starts from μ-chloro-bridged dimers L 2 Ir(μCl) 2 IrL 2 . Further reaction of these precursors with an excess of dbppyH at temperatures of 95–120 °C leads to the target complexes only in the case of the phenylpyridine based precursors (L = ppy and dfppy). All complexes were characterized via 1D and 2D NMR spectroscopic methods. All the facial tris -cyclometallated complexes exhibited strong absorptions between 200 and 320 nm typical of a π → π ∗ transition together with weaker MLCT absorptions below 320 nm. The emission spectra of all these luminescent Ir(III)-complexes cover the region between approximately 500 to 700 nm. This strongly supports the hypothesis that the luminescent properties are controlled mainly by the dbppy ligand. The lifetimes of the complexes are quite different relative to each other and are much shorter than their homoleptic Ir(L) 3 counterparts. [ABSTRACT FROM AUTHOR]

Aromatic polyether ether ketones are polymers whose volume of production is now increasing at a rapid rate, which is due to the important array of service properties of these polymers. Certain processing characteristics of composites based on polyether ether ketones are considered in this paper. [ABSTRACT FROM AUTHOR]

ABSTRACT: Partially sulfonated poly(aryl ether sulfone) (PESS) was synthesized and methacrylated via reaction with glycidyl methacrylate (PESSGMA) and cross‐linked via radical polymerization with styrene and vinyl‐phosphonic acid (VPA). The chemical structures of the synthesized pre‐polymers were characterized via FTIR and 1H NMR spectroscopic methods and molecular weight was determined via GPC. Membranes of these polymers were prepared via solution casting method. The crosslinking of the PESS polymer reduced IEC, proton conductivity, swelling in water, and methanol permeability of the membranes while increasing the modulus and the glass transition temperature. However, the introduction of the VPA comonomer increased the proton conductivity while maintaining excellent resistance to methanol cross‐over, which was significantly higher as compared with both PESS and the commercial Nafion membranes. Membranes of PESSGMA copolymers incorporating VPA, exhibited proton conductivity values at 60 °C in the range of 16–32 mS cm−1 and methanol permeability values in the range of 6.52 × 10−9 – 1.92 × 10−8 cm2 s−1. © 2018 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2018, 56, 558–575 [ABSTRACT FROM AUTHOR]

In this work, 2,5-bis(4-fluorophenyl)-1,3,4-oxadiazole (2F-Oz) is synthesized and successfully polymerized with 4-(4-hydroxyaryl)-phthalazin-1-one (DHPZ) through polycondensation to produce poly(ether 1,3,4-oxidiazole) containing phthalazinone units (PPEO) with intrinsic viscosity 1.54 dL g−1. A series of sulfonated poly(ether-1,3,4-oxidiazole)s (SPPEOs) with different degrees of sulfonation are prepared via postsulfonation reaction. The chemical structure of PPEO and SPPEOs was characterized through FT-IR and proton nuclear magnetic resonance, respectively. SPPEOs have excellent film-forming properties and readily dissolve in polar aprotic solvents, such as dimethyl sulfoxide, N-methyl-2-pyrrolidone (NMP), and so on. The water uptake of these SPPEO membranes with measured ion-exchange capacity of 1.13–1.61 mmol g−1 was 15.7–34.1% at 25°C and 17.9–59.8% at 60°C, and swelling ratio was 5.9–14.2% at 25°C and 6.6–18.1% at 60°C, respectively. The proton conductivity of SPPEO-1.61 is 0.045 S cm−1 at 30°C and 0.065 S cm−1 at 80°C, and the tensile strength of the SPPEO-1.61 is 48 MPa, and its elongation at break was 21%. The thermal and chemical stability of the SPPEOs is also examined. [ABSTRACT FROM AUTHOR]

Pervaporation membranes made from polyethersulfone (PESU), polyphenylsulfone (PPSU), polytrimethylphenylethersulfone (T-PESU) and hydrophilic PESU-co-Pluronic (H-PESU) polymers were evaluated for dehydration of ethanol and methanol. Fundamental characteristics of pore structure, free volume, d-spacing, water contact angle, water and ethanol uptakes were investigated and correlated with their dehydration performance. The H-PESU membrane shows the best ethanol dehydration performance due to its synergetic combination of the strengths from both rigid hydrophobic PESU and flexible hydrophilic Pluronic moieties. It has the highest water permeability of 0.322 mg m −1  h −1  kPa −1 which is 2–6 times higher than other three membranes because the hydrophilic Pluronic moiety may form special water transport channels. It also has a comparable mole-based selectivity of 685 due to the rigid hydrophobic PESU moiety that prevents the membrane from uncontrolled swelling. Long-term tests evidence the operating stability of both H-PESU and PESU membranes. In addition, the methanol dehydration performance of these membranes is superior to the other reported polymeric membranes. The water in the permeate can be concentrated to 86.8%. These promising preliminary results suggest that these polyarylether (PAE) membranes have great potential for ethanol and methanol dehydration. [ABSTRACT FROM AUTHOR]

A series of novel blend ultrafiltration (UF) membranes have been successfully prepared from commercial poly (ether sulfone), lab-synthesized sulfonated poly (aryl ether sulfone) (SPAES, 1 wt%) and copper nanoparticles (0 ∼ 0.4 wt%) via immersion precipitation phase conversion. The micro-structure and separation performance of the membranes were characterized by field emission scanning electron microscopy (SEM) and cross-flow filtration experiments, respectively. Sodium alginate, bovine serum albumin and humic acid were chosen as model organic foulants to investigate the antifouling properties, while E. coil was used to evaluate the antibacterial property of the fabricated membranes. By the incorporation with SPAES and copper nanoparticles, the hydrophilicity, antifouling and antibacterial properties of the modified UF membranes have been profoundly improved. At a copper nanoparticles content of 0.4 wt%, the PES/SPAES/nCu(0.4) membrane exhibited a high pure water flux of 193.0 kg/m 2 h, reaching the smallest contact angle of 52°, highest flux recovery ratio of 79% and largest antibacterial rate of 78.9%. Furthermore, the stability of copper nanoparticles inside the membrane matrix was also considerably enhanced, the copper nanoparticles were less than 0.08 mg/L in the effluent during the whole operation. [ABSTRACT FROM AUTHOR]

We constructed a dual ligands-modified nanostructured lipid carrier (NLC) called PAR-NLC, in which the epidermal growth factor receptor (EGFR)-targeted small peptide AEYLR was attached to the distal end of PEG2000anchored on the NLC surface naming PEG-AEYLR, and poly-arginine (R8) as a classic cell-penetrating peptide was attached directly to the NLC surface. PAR-NLC was near-spherical particle with average size ∼50 nm and zeta potential at +14.09 mV; the cellular uptake of PAR-NLC showed synergistic effect of the two peptides, presented as significant superior cellular uptake in EGFR-positive cells NCI-H1299 and S180 over EGFR-negative cell K562. In the animal optical imaging study, 2 h after the administration of the Dir-loaded PAR-NLC, maximum Dir signal appeared in tumor tissue, indicating prompt tumor targeting effect, as time prolonged to 48 h, the Dir signal attenuated in the organs except tumor, suggesting constant clearance from the body. In thein vivoantitumor study, in premise of the same dose, paclitaxel-loaded PAR-NLC exhibited better antitumor and safety effect than Taxol, the body weight of the mice was more stable and tumor size was smaller. In summary, PAR-NLC was a potential drug carrier to deliver anticancer drugs safely and effectively. [ABSTRACT FROM AUTHOR]

Aromatic poly(ether-ether-ketone)s (PEEKs) have received much attention to be used in biomedical field, due to their good physicochemical properties, processability and biocompatibility. Metal-exchanged zeolites have demonstrated to be good biomaterials in various applications, because of their low-toxicity, functional groups for grafting and high dispersibility. In this study, new materials based on silver-containing zeolite L (Ag-ZL) and a PEEK containing phthalide units and pendant carboxylic groups were prepared. The films were characterized by FTIR spectroscopy, scanning electron microscopy and humidity absorption measurements. Their antimicrobial activity and cytotoxicity were investigated. The films having 12% Ag-ZL showed antimicrobial activity against Gram positive bacteria ( Staphylococcus aureus 25923 ATCC and Staphylococcus aureus MRSA 43300 ATCC) and Gram negative bacteria ( Escherichia coli 25922 ATCC) while those having 2% Ag-ZL were active only towards Gram positive bacteria. All the samples exhibited reduced cytotoxicity being thus potential candidates for biomedical applications. [ABSTRACT FROM AUTHOR]

ABSTRACT Thermoplastic elastomers composed of soft and hard segments are important elastic and processable synthetic polymers. The microphase-separated soft domains show low glass transition temperature and possess sufficient chain mobility at room temperature. In this study, we report the synthesis and healing properties of multiblock copolymers containing disulfide bonds as dynamic covalent bonds. The multiblock copolymers composed of poly(arylether sulfone) and poly(alkylthioether) segments were synthesized by oxidative coupling polymerization of the corresponding thiol-terminated oligomers. Atomic force microscopy phase images, differential scanning calorimetry, and dynamic mechanical analysis curves indicated the microphase-separated morphology of the multiblock copolymer. Self-healing properties of the polymer were evaluated by changes in the elongation at break of the cut/adhered samples. The elongation recovery increased with UV irradiation time, and the multiblock copolymer showed a 93% recovery after UV irradiation for 5 h. The healing efficiency induced by UV irradiation, determined by subtracting the recovery without UV irradiation, was calculated to be 51%. According to the UV spectra and solubility changes after UV irradiation, the main healing factor in this study was the crosslinking reactions caused by thiyl radicals generated from UV irradiation instead of disulfide exchange reactions. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 3545-3553 [ABSTRACT FROM AUTHOR]

In the present study a high performance polymer poly aryl ether ketone (PAEK) is reinforced with micro and nano boron carbide (BC) and functionalized multi walled carbon nanotubes (F-MWCNT) to investigate the individual and hybrid effect of the fillers. Optical microscopy and transmission electron microscopy suggested the dispersion of micro and nano fillers respectively in PAEK matrix. The inclusion of BC nano fillers increased the hardness of the composites which aided the wear resistance of the composites. The morphological features of the worn surface of the samples are analyzed using scanning electron microscopy. It is found from the izod impact test analysis that the impact strength of the composite enhanced by the F-MWCNT inclusion. The thermal properties of PAEK in the composites are studied using differential scanning calorimetry and it revealed dominant effect of F-MWCNT influencing the thermal transitions than the BC particles. The kinetics of thermal degradation of various composites is analyzed using Coats-Redfern method. The positive influence of BC in the matrix indicates that the thermal degradation is delayed due to the higher activation energy it possesses. The overall results shows that the hybrid nanocomposite exhibits better properties compared to individual micro and nano composites. [ABSTRACT FROM AUTHOR]

Copper tetra-amine phthalocyanine ( NH2-CuPc) was grafted onto barium titanate ( BaTiO3) whose surface was modified by carboxylic polyarylene ether nitrile ( CPEN) to afford a nano-filler ( CPEN-f- BaTiO3@ NH2-CuPc). Through a solution-casting method combined with ultrasonic dispersion technology, the obtained CPEN-f- BaTiO3@ NH2-CuPc was successfully incorporated into biphenyl polyarylene ether nitrile ( BP-PEN) matrix to prepare nanocomposite films with various mass fractions of CPEN-f- BaTiO3@ NH2-CuPc (0, 2.0, 5.0, 10.0 and 20.0 wt%). After that, the nanocomposite films were unidirectionally stretched with various stretching ratios at 280 °C. All the nanocomposite films show excellent mechanical and thermal stability, which is provided by the BP-PEN matrix. The crystallinity and mechanical, thermal and dielectric properties of the nanocomposite films are efficiently enhanced after the unidirectional hot-stretching process. The results show that hot-stretching is a useful method for improving the mechanical and crystallization behaviors as well as the thermal and dielectric properties of the nanocomposite films. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

In this paper, polyaryl polymethylene isocyanates (PAPI) were used as an innovative alternative material to prepare isocyanate microcapsules. PAPI could be used as core materials, which would react with small molecules containing active hydrogen (1,4-butanediol, ethylene glycol, 1,2-diaminoethane etc.). The reaction products of PAPI and active hydrogen would form a shell by interfacial polymerization reaction in an oil-in-water emulsion. Smooth spherical microcapsules of 70 ~ 180 μm in diameter were produced by controlling agitation rate (600 ~1200 rpm). High yields (~80%) of a free-flowing powder of PAPI/polyurethane and polyurea capsules were produced with a high isocyanate groups (-NCO) content of 23 wt % as determined by titration analysis. Structural analysis and quality assessments of each batch of microcapsules were performed by using thermogravimetric analysis, Fourier transform infrared spectroscopy and scanning electron microscopy. Preliminary results indicated the microcapsules were stable with only about 20% loss of -NCO detected after one month storage under ambient conditions. This work showed the great potential of novel microencapsulation technique in development of protection of -NCO and in aspects of micro- and nano-structure construction materials. [ABSTRACT FROM AUTHOR]

This paper discusses various methods of fabrication of plain and carbon-reinforced composite powders, as well as a range of powder characterisation test methods suitable for defining powders for laser sintering. Two milling processes (based on disc blades and rotatory cutting knives) were used as methods of fabrication of powders, starting from injection moulding granule grades, for comparison with current powders obtained directly from polymerisation processes. It was found that the milling process affects the particles properties. The rotary milling produced powders with superior properties in comparison with the disc milling method. Tests including particle size distribution, angle of repose, aspect ratio, sphericity and roundness of particles were employed to compare and assess the suitability of powders for laser sintering. The Brunauer-Emmett-Teller test was identified as a useful method to define surface roughness and porosity of the particles. The carbon fibre (Cf) Poly Ether Ketone (PEK) granules milled well and after an additional sieving process created a good quality powder. This is the first attempt to investigate properties of PEK powder with encapsulated Cf and follow their sintering profile through hot-stage microscopy. It is expected that this type of composite powder will create isotropic structures in comparison with the highly anisotropic properties given by the known dry mix composite powders, currently used in laser sintering. [ABSTRACT FROM AUTHOR]

The increasing use of PEEK (poly-ether-ether-ketone) as a substitute for metal implant components has led to the suggestion that it could also be used as an alternative to titanium in the field of dental implants. A major requirement for dental implant materials is their resistance to cyclic loading due to mastication. A special fatigue test was designed to evaluate the elastic behavior and long-term form stability of cylindrically shaped PEEK specimens of 4, 5 and 6 mm in diameter, using 11 different PEEK materials of various grades: unfilled, filled with titanium dioxide or barium sulfate powder, reinforced with short carbon fibers or short glass fibers, and reinforced with continuous carbon fibers. The samples were exposed to cyclic loads of up to 2000 N. The elastic limits ranged between 46.57±6.44 MPa for short carbon fiber reinforced specimens of 6 mm diameter and 107.62±8.23 MPa for samples of a different short carbon fiber reinforced PEEK compound of 4 mm diameter. The elastic limits of the two PEEK grades containing continuous carbon fibers could not be observed because they exceeded the limits of the test specification. The elastic moduli ranged between 2.06±0.18 GPa for barium sulfate powder filled PEEK-specimens of 6 mm diameter and 57.53±14.3 GPa for continuous carbon fibers reinforced PEEK-specimens of 4 mm diameter. In terms of the elastic limit all the PEEK materials in consideration were able to resist the pressure caused by maximum masticatory forces. [ABSTRACT FROM AUTHOR]

An effective method was proposed to prepare low dielectric constant composites based on a hybrid of graphene oxide–POSS and fluoropoly(ether ether ketone) (FPEEK). Through the formation of amide between aminopropylisobutyl polyhedral oligomeric silsesquioxane (POSS-NH2) and oxygen-containing groups (carboxyl groups) on graphene oxide (GO), the covalent functionalization of GO with POSS-NH2 (POSS-NH2–GO) hybrid was carried out, which is highly soluble in many organic solvents. The structure of the POSS-NH2–GO hybrid was confirmed by FT-IR, Raman, XRD, TGA, XPS, and TEM. The POSS-NH2–GO hybrid was well dispersed within the FPEEK polymer matrix to prepare POSS-NH2–GO/FPEEK composite films by solution blending. The dielectric constants of the composites decreased with the increasing content of POSS-NH2–GO hybrid, and a κ value of 2.01 was achieved with the incorporation of the hybrid, only 3.0 wt% could cause a 92.8% high enhancement in Young's modulus. [ABSTRACT FROM AUTHOR]

A new efficient method was developed for the synthesis of triaryl-substituted cyclohexenones and salicylates. The method is based on the Robinson annulation of readily available keto esters and chalcones, followed by the aromatization of the cyclohexenone moiety. The aromatization can be accomplished either by reaction with bromine in boiling chloroform or bromination with copper(II) bromide in ethanol followed by treatment with pyridine or 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU). The new synthetic method was also implemented in a onepot protocol, which in some cases resulted in higher yields of the final product compared to those obtained in the stepwise synthesis. [ABSTRACT FROM AUTHOR]

The rapid achievement of high strength adhesive is of ever increasing importance for underground construction. Herein, a simple and effective strategy to make an adhesive in a “high early strength” way was based on excellent crosslinking and synergistic interactions among tripolyglycerol, waterglass and polyaryl polymethylene isocyanate (PAPI). The resultant organic-inorganic hybrid adhesive with three-dimensional interpenetrating network structure showed an excellent mechanical performance, the compressive strength could reach more than 50 and 60 MPa after curing for 2 and 4 h, respectively. The adhesive was mainly composed of amorphous polyurethane and crystalline polysilicic acid/NaHCO 3 composite, and its probable formation mechanism was proposed. Furthermore, the adhesive was thermally stable below 260 °C and presented a favorable adhesion performance for dry/wet sands with various sizes. This work may open a simple and convenient avenue for the preparation of organic-inorganic hybrid adhesive with high early strength. [ABSTRACT FROM AUTHOR]

ABSTRACT This work describes the development of porous membranes based on blends of an aromatic polyether bearing main and side chain pyridine units (AP) with hydrophilic ionic polymers, like poly(sodium 4-styrenesulfonate) (PSSNa) and its acid form (PSSH), or non-ionic like polyvinylpyrrolidone and polyethylene glycol. Porous membranes were obtained after the removal of the water soluble polymers from the respective blend. The effect of various parameters such as water soluble polymer used (pore former), blend composition, casting solvent, and solvent evaporation level on porous structure formation was studied thoroughly. Specifically, SEM examination for the aforementioned systems indicated various porous morphologies depending on experimental conditions as well as thermodynamic and kinetic parameters occurring during their formation. The thermal properties of the membranes were influenced by the kind of the pore former, as revealed by thermogravimetric analysis. Special attention was paid to the systems AP/PSSNa and AP/PSSH to evaluate their miscibility via dynamic mechanical analysis and ATR-FTIR spectroscopy. AP/PSSNa membranes have been preliminary used to test the water permeability for water purification. The tests revealed high water flux values at increased PSSNa concentrations. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44539. [ABSTRACT FROM AUTHOR]

ABSTRACT Interest in carbon fiber reinforced composites based on polyaryl ether ketones (PAEKs) continues to grow, and is driven by their increasing use as metal replacement materials in high temperature, high-performance applications. Though these materials have seen widespread use in oil, gas, aerospace, medical and transportation industries, applications are currently limited by the thermal and mechanical properties of available PAEK polymer chemistries and their carbon fiber composites as well as interfacial bonding with carbon fiber surfaces. This article reviews the state of the art of PAEK polymer chemistries, mechanical properties of their carbon fiber reinforced composites, and interfacial engineering techniques used to improve the fiber-matrix interfacial bond strength. We also propose a roadmap to develop the next generation of high-performance long fiber thermoplastic composites based on PAEKs. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44441. [ABSTRACT FROM AUTHOR]

Thioacetylation poly(aryl ether ketone) (AcSPEK-C) as the precursor of thoilation poly(aryl ether ketone) (SHPEK-C) was synthesized via chloromethylation and thioacetylation of a phenolphthalein poly(aryl ether ketone) (PEK-C) successively. Then AcSPEK-C nanofiber mat was prepared by electrospinning technique, after the deacetylation and the acidification reaction, the SHPEK-C nanofiber mat with the average diameter of 570 nm (SEM test) was successfully obtained ultimately. DSC test showed that SHPEK-C had a single glass transition temperature ( T =300°C). Adsorption isotherms and adsorption kinetics of the static adsorption process were used to examine the fundamental adsorption properties of Hg ions. The results showed that the maximum adsorption capacity was 3.75 mmol Hg g. In addition, the SHPEK-C superfine fibrous membrane also showed high recyclable removal efficiency through the adsorption/desorption experiments. [ABSTRACT FROM AUTHOR]

Aluminum nitride (AlN) with high thermal conductivity was blended in polyarylene ether nitrile (PEN) to obtain a composite system. A ball milling process could provide AlN particles of smaller size with higher surface silylation for homogeneous particle distribution in polymeric matrix. Thermal, electrical, and mechanical behaviors of the produced composites were characterized to investigate the effects of particles on the performance of PEN-based composites with functionalized AlN. The composite exhibited thermal conductivity of 0.779 W m−1 K−1, a dielectric constant of 7.7, dielectric loss of 0.032, electrical resistivity of 1.39 GΩ.cm, and break strength of 36 N when the fraction of functionalized AlN increased to 42.3 vol%. A fitted equation based on the improved Russell's model could effectively predict a trend for thermal conductivity of the composite systems with consideration of interfacial resistance between AlN and surrounding PEN. POLYM. COMPOS., 37:3033-3041, 2016. © 2015 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]

Quaternized adamantane-containing poly(aryl ether ketone) anion exchange membranes (QADMPEK) are prepared and investigated for vanadium redox flow batteries (VRFB) application. The bulky, rigid and highly hydrophobic adamantane segment incorporated into the backbone of membrane material makes QADMPEK membranes have low water uptake and swelling ratio, and the as-prepared membranes display significantly lower permeability of vanadium ions than that of Nafion117 membrane. As a consequence, the VRFB cell with QADMPEK-3 membrane shows higher coulombic efficiency (99.4%) and energy efficiency (84.0%) than those for Nafion117 membrane (95.2% and 80.5%, respectively) at the current density of 80 mA cm −2 . Furthermore, at a much higher current density of 140 mA cm −2 , QADMPEK membrane still exhibits better coulombic efficiency and energy efficiency than Nafion117 membrane (coulombic efficiency 99.2% vs 96.5% and energy efficiency 76.0% vs 74.0%). Moreover, QADMPEK membranes show high stability in in-situ VRFB cycle test and ex-situ oxidation stability test. These results indicate that QADMPEK membranes are good candidates for VRFB applications. [ABSTRACT FROM AUTHOR]

A bioinspired iron-catalyzed consecutive oxidative cross-coupling reaction between a single phenolic unit and nucleophilic arenes was developed. This sustainable transformation offers a selective synthetic strategy for the preparation of complex polyaryl compounds directly from readily available phenols. With the aid of electron paramagnetic resonance spectroscopy, it was demonstrated that the groups ortho to the phenolic functionality (whether hydrogen, methyl, or methoxy) direct the regioselectivity (ortho, para, or meta via dienone-phenol rearrangement) and chemoselectivity (C-C coupling or C-O coupling) in this multistep process. [ABSTRACT FROM AUTHOR]

A novel type of graphite (thermographite) having higher thermal conductivity (TC) due to a patented treatment is commercialized recently. It was anticipated that such particles would be more effective in conducting away frictional heat generated on the tribo-surfaces leading to the enhanced performance. Hence two composites were developed based on high performance Polyarylether ketone (PAEK) (50% by wt) containing 30% short glass fibers (GF) and hexa-boron nitride (hBN) 10% apart from 10% graphite. First composite designated as C NG contained 10% natural graphite (NG) while the other designated as C TG contained 10% thermographite (TG). These were processed by identical method (twin screw extrusion followed by injection molding). The tribo-performance was evaluated in a pin on disc (mild steel) configuration under very high load and speeds. It was observed that both the composites exhibited excellent tribo-performance. However, C NG performed better than the C TG in all respects only under severe operating conditions. Under low PV conditions, difference was not clear. It showed lower friction coefficient, and wear rate as compared to C TG . C NG showed PV limit value 96.6 MPa-m/s which was decisively superior to C TG (91 MPa-m/s). C NG could sustain higher speed (3.45 m/s) than the C TG (3.25 m/s) under 900 N in spite of slightly lower TC. It was concluded that during treatment (patented by the company) TG has slightly distorted layer-lattice structure as compared to the natural graphite, which could be responsible for transferring less beneficial film under severe operating conditions. SEM and EDAX studies were conducted to understand wear mechanisms. Such composites with such high PV limit values low, µ (0.04) and low wear rates (1×10 − 16 m 3 /Nm) are not reported in the literature and may prove as ideal materials for dry bearings in harsh operative conditions. [ABSTRACT FROM AUTHOR]

ABSTRACT We describe the synthesis of a novel electroactive photo-crosslinkable poly(aryl ether), containing tetraaniline pendants and allyl groups (EPPAE). The polymer structure and spectral properties are studied in detail. By introducing the electroactive tetraaniline pandents, EPPAE reveals reversible electrochemical activity, expected electrochromic behavior and good anticorrosive performance. After crosslinking the allyl groups with UV exposure, the resultant polymer (c-EPPAE) shows drastic change in electrochemical properties. The c-EPPAE/ITO electrode exhibits declining electroactivity but excellent electrochemical stability, which are associated with densification of the electroactive layer. Furthermore, in the corrosive protection measurements, c-EPPAE reveals an outstanding protection efficiency (99.92%) for stainless steel substrates. A comprehensive study of electrochromic properties and corrosive protection of EPPAE before and after UV exposure will provide an insightful tool for the developing electrochromic smart windows, electrochromic displays, and anticorrosive paint. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2321-2330 [ABSTRACT FROM AUTHOR]