Polyphenyl Ether Research Articles

Gradient side chain grafted anion exchange membranes for fuel cell applications

This study reports on the synthesis, design and evaluation of a novel, interesting type of gradient-side-chain polyphenyl ether anion exchange membranes (AEMs) as the electrolytes for alkali fuel cells. Such membranes were fabricated by co-grafting of quaternized side chains with different lengths onto the polymer backbone. Based on our transmission electron microscopy and small angle X-ray scattering results, the gradient side chain structured AEM can enhance microphase and produce significantly larger ion clusters than that with purely long side chains; this is probably because the gradient side chain structure can possibly reduce the steric hindrance and facilitate cation aggregation during microphase separation. The gradient side chain AEM exhibited enhanced conductivity of hydroxide ions (107.7 mS cm−1 at 80 °C) compared to the uniform-side-chain membrane. It also demonstrated superior alkaline stability, retaining ca. 80% of conductivity and ion exchange capacity after a harsh alkali treatment at 80 °C in 1 M NaOH for 552 hours. Our study preliminarily demonstrates that gradient side chain structure is advantageous over conventional uniform side chains in promoting microphase separation of AEM, and deserves further investigations to optimize the gradient structure for better membrane performance.

Preparation and Property Study of PA56/POE-g-MAH-GMA/PPO Ternary Alloy

Bio-based PA56 is as matrix resin, maleic anhydride (MAH), and glycidyl methacrylate (GMA) dual monomer grafted POE (POE-g-MAH/GMA) polyphenyl ether(PPO) are simultaneous as toughening agents. The PA56/POE-g-MAH-GMA/PPO ternary alloys containing 10 wt% POE-g-MAH-GMA with different PPO content prepared by the melt blending method through twin screw extruder. The structure and property of PA56/POE-g-MAH-GMA/PPO ternary alloys were studied. The results showed that the microscopic morphology of each alloy showed an obvious “sea-island” structure. PA56 is a continuous sea phase, and the island phase assumes the “core–shell structure,” the etched POE-g-MAH-GMA particles are as the nucleus, and PPO are as the shell. When the PPO mass fraction is 30%, the relative crystallinity of the alloy is 11.56%, which is 1.68 times lower compared to the pure PA56, the alloy notch impact strength is 42.1 kJ/m2, and reaches 11.7 times of pure PA56; the water absorption rate of 1.22%, which is 3.22 times lower than pure PA56.

Organic Vacuum Pump Fluids for the Vacuum Pumping of Fusion Power Plants

Vacuum pumps are the heart of the fusion fuel cycle, but most currently proposed pumping technologies are not capable of handling the required flow rates and vacuum pressures. Oil-containing vacuum pumps can readily meet the flow requirements, but vacuum fluids will degrade in fusion-relevant environments due to contact with tritium and exposure to high-energy radiation. Here, we describe a methodology to screen vacuum fluid candidates and purify these candidate fluids post oxidation, post exposure to deuterium, and post exposure to gamma radiation (<7.5 MGy) to simulate a process in which vacuum fluids can be recovered and regenerated during the fusion fuel cycle. A series of oils, including a highly purified mineral oil, phenyl silicone oil, and a polyphenyl ether, are shown to be suitable candidates for vacuum pumping. Additionally, we describe a simple purification methodology to remove oxidized functionalities and the associated isotopologues induced by contact with deuterium from the candidate vacuum fluids This purification methodology can also be applied to radiological damage with moderate effect. Finally, we demonstrate that the sorbents can be regenerated through electromagnetic microwave digestion.

Thermal, mechanical and dielectric property enhancement of benzoxazine-containing phthalonitrile resin: The effect of functional oligomeric polyphenyl ether

Two oligomeric polyphenyl ethers (PPE) with different functional groups (hydroxyl group and allyl group) were introduced into the benzoxazine-containing phthalonitrile resin, in order to improve the dielectric properties. The polymerization mechanism of the two systems was investigated in detail and the comprehensive properties were studied. It was found that both hydroxyl-terminated PPE (PH) and allyl-terminated PPE (PA) could effectively promote the curing of phthalonitrile resin, while the PH system showed higher activity. Nevertheless, PH could not polymerize and chemically bonded with the crosslinking network. While the allyl groups in PA, however, could self-polymerize or copolymerize with phthalonitrile resin and the thermal resistance and dimensional stability improved as a consequence. PA system shows better dielectric properties, due to the low polarity of functional groups. Poly(MBP-30PA) showed the lowest dielectric constant of 2.88 at 1 MHz. Additionally, the mechanical strength of the glass fiber reinforced composites was also improved. G(MBP-20PA) showed flexural strength of 561.8 MPa, 155.1 MPa higher than that of G(MBP).

Alkylated Polyphenyl Ethers as High-Performance Synthetic Lubricants

Lubricants exhibiting both thermal and chemical stability that consequently generate less hydrogen during friction are required to avoid the hydrogen embrittlement of moving mechanical components. The present work studied the effects of the length and number of alkyl chains on the tribological properties of polyphenyl ethers (PPEs), which feature good thermal and radiation resistance. PPEs were found to have much lower friction coefficients compared with a poly-alpha-olefin and alkyldiphenyl ether, and the effect of the running-in process on friction appeared to be negligible. The formation of polymers on the friction track evidently decreased the friction coefficients of the lubricants and the wear rates were almost zero for all the PPEs, indicating excellent anti-wear properties. Analyses with a quadrupole mass spectrometer connected to a friction tester under vacuum indicated negligible hydrogen generation from 4P2E, which had no alkyl chains, after the running-in. R1-4P2E, having a C16H33 chain, showed hydrogen desorption similar to that of the alkyldiphenyl ether, which had a C18H37 alkyl chain. R2-4P2E, with two C16H33 chains, produced significant hydrogen, but with a long induction period; thus, it provided good wear protection. Although alkyl chains increased the risk of hydrogen generation, PPEs with such chains may have applications as standard lubricants.

Characterization of a polyphenyl ether oil irradiated at high doses in a TRIGA Mark II nuclear reactor

Samples of a commercially available polyphenyl ether (PPE) oil are irradiated in the mixed neutron and gamma radiation field of the Pavia TRIGA Mark II reactor, at irradiation doses ranging from 0.78 MGy to 7.8 MGy. The oil is a nuclear grade product, whose radiation resistance reported in the product specification is based on cobalt-60 gamma irradiation data. The collection of additional data in a nuclear reactor radiation field performed in the present work, is motivated by the need to use this oil in neutron-rich environments such as targets and accelerators.The post-irradiation characterization of the oil samples here reported includes viscosity measurements, total acid number (TAN), Fourier transform infrared spectroscopy (FT-IR), gas chromatography (GC), gel permeation chromatography (GPC) and nuclear magnetic resonance (NMR) spectroscopy.The presented results evidence a remarkable increase of kinetic viscosity with the absorbed dose. Differences in the radiation-induced viscosity increase are observed comparing the data collected in mixed neutron and gamma radiation with the previous ones collected in cobalt-60 gamma radiation. This result emphasizes the need of further studies on the dependence of the radiation damage on different radiation environments. A negligible increase of TAN is reported. The FT-IR, GC, GPC and NMR show progressive polymerization with increasing dose. The increasing molecular size is in line with the viscosity data presented.

Vapor-phase chromatography in glass-capillary column of high polar and involatile hydrocarbon-containing ether derivatives of disulpho-benzoic acid

The paper deals with the results of capillary columns implementation in vapor-phase chromatography. Glass and narrow-bore columns covered with liquid stationary phase and polyphenyl ether were used, the mixtures of aliphatic alcohols, acids, amines and ether derivatives of disulpho-benzoic acid, which are semi-products of additive synthesis analyzed. The usage of water vapor as a moving carrier of nitrogen enabled to decrease the analysis time and improve division efficiency. The retention time, height values of equivalent theoretic plates and coefficient of analyzed components asymmetry were calculated. Obtained results justify the practicability of glass capillary application for the analysis of disulpho-benzoic acid derivatives via vapor-phase chromatography method.

PCB Laminates for Automotive Radar Antenna Modules Under Different Environmental Conditions

Radar systems have become more important in the automotive field, especially for autonomous driving. A crucial part of the hardware is the antenna which is connected by lines to the radar chip. These components are usually built on printed circuit boards (PCBs) that have to fulfill high automotive requests under all environmental conditions. As a consequence, material properties are a critical factor for the functionality and reliability of systems, like-wise new materials are available in the market. Fourteen interesting materials of different classes [polytetrafluorethylene (PTFE), polyphenyl ether (PPE), epoxy-based resin, and liquid crystal polymer (LCP)] were evaluated in this work at their initial state, while heating to 125 °C and after storage with 85% relative humidity (RH) at 85 °C. It is shown that there are new candidates for millimeter wave applications beyond the PTFE materials. Nevertheless, it is necessary to test each material individually for its properties and optimize the parameters in simulation because they differ from the values in the datasheet. In addition, the properties depend on the used line setup, in this work microstrip lines. For the measurements, multiline thru-reflect-line (TRL) calibration and ring resonators were used and give a good overview by loss and effective permittivity depending on the environmental condition.

Electric-field-aligned functionalized-layered double hydroxide/polyphenyl ether composite membrane for ion transport

Abstract To address the insufficient ion conductivity of hydroxide exchange membranes (HEMs) used in alkali membrane fuel cells (AMFCs), we present a series of aligned layered double hydroxide (LDH)/polyphenyl ether (PPO) composite membranes based on the electrorheological effect. The hexagonal LDH was functionalized with N-spirocyclic ammonium (ASU-LDH) to enhance the electrorheological effect of the ASU-LDH as well as improve the ion conductivity of the ASU-LDH. The aligned ASU-LDH/triple-cation-functionalized PPO (ASU-LDH/TC-PPO) composite membranes were prepared by applied-electric field. The effective electric-induced ion channels (EICs) were constructed by aligned ASU-LDH nanosheets in HEMs, which are distinctly observed by scanning electron microscope (SEM). Notably, these EICs-contained ASU-LDH/TC-PPO composite membranes exhibit the higher ion conductivity and alkaline stability than those of normal TC-PPO and ASU-LDH/TC-PPO membranes. It is worth noticing that these EICs are different with the traditional phase-induced ion channels, the EICs show the shorter ion transport distances and broader water channels in HEMs. Attributing to EICs, the longitudinal ion conductivity of aligned ASU-LDH/TC-PPO membrane shows 32.2% and 18.7% improvement compared to pristine TC-PPO and normal ASU-LDH/TC-PPO membrane. The maximum ion conductivity of the aligned ASU-LDH/TC-PPO composite membrane reaches to 109.8 mS/cm at 80 °C. The long-term stability test shows that the aligned ASU-LDH/TC-PPO membranes still exhibit enhancing alkali resistance (83.2%) in 1 M KOH at 80 °C for 500 h. In brief, this work provides a novel and effective approach to prepare high-performance HEMs.

Robust poly(aryl piperidinium)/N-spirocyclic poly(2,6-dimethyl-1,4-phenyl) for hydroxide-exchange membranes

Herein, for realizing the high efficiency and long lifetime of hydroxide exchange membranes (HEMs) for alkaline membrane fuel cell (AMFC) applications, a series of robust poly(biphenyl piperidinium) (PBP)/6-azaspiro[5.5] undecane (ASU)-functionalized polyphenyl ether (ASU-PPO) membranes were prepared by a crosslinked strategy. Crosslinked PBP-ASU-PPO membrane combines the advantage of PBP and ASU-PPO membranes as well as addresses the problem of high water uptake of PBP and the insufficient film-forming property of ASU-PPO. As expected, these crosslinked PBP-ASU-PPO membranes exhibit commendably comprehensive performances, such as good ion conductivity, durability, and mechanical properties. The crosslinked PBP-ASU-PPO membrane reaches a maximum OH− conductivity of 128 mS/cm at 80 °C, accompanying with a 15.7% membrane swelling. Besides, only 13.6% degradation in Cl− conductivity was observed in PBP-ASU-PPO after alkaline treatment in 1 M NaOH at 80 °C for 2000 h. Besides, the selected PBP-ASU-PPO membrane achieves a maximum power density of 324 mW/cm2 at current density of 750 mA/cm2.

Ultrastable and High Ion-Conducting Polyelectrolyte Based on Six-Membered N-Spirocyclic Ammonium for Hydroxide Exchange Membrane Fuel Cell Applications.

In response to prepare high-stable and ion-conducting polyelectrolyte for hydroxide exchange membrane (HEM) applications, we present an ultrastable polyelectrolyte based on six-membered heterocyclic 6-azonia-spiro[5.5]undecane (ASU) and polyphenyl ether (PPO). A series of ASU-functionalized PPO polyelectrolytes (ASU-PPO), which can be easily dissolved in low-boiling pointing solvent, have been successfully synthesized by a remote-grafting method. The ASU precursor is stable in 1 M NaOH/D2O at 80 °C for 2500 h as well as in 5 M NaOH/D2O at 80 °C for 2000 h, and the predicted half-life of the ASU precursor would exceed 10 000 h, even higher in the future. Besides, these remote-grafting ASU-PPO polyelectrolytes are stable in 1 M NaOH(aq) at 80 °C for 1500 h. Robust and pellucid segmented ASU and triple-ammonium-functionalized PPO-based HEMs attach OH- conductivity of 96 mS/cm at 80 °C and realize maximal power density of 178 mW/cm2 under current density of 401 mA/cm2.

In Vitro and in Silico Competitive Binding of Brominated Polyphenyl Ether Contaminants with Human and Gull Thyroid Hormone Transport Proteins.

Tetradecabromo-1,4-diphenoxybenzene (TeDB-DiPhOBz) is a highly brominated additive flame retardant (FR). Debrominated photodegradates of TeDB-DiPhOBz are hydroxylated in vitro in liver microsomal assays based on herring gulls (Larus argentatus), including one metabolite identified as 4″-OH-2,2',2″,4-tetrabromo-DiPhOBz. Chemically related methoxylated tetra- to hexabromo-DiPhOBzs are known contaminants in herring gulls. Collectively, nothing is currently known about biological effects of these polybrominated (PB) DiPhOBz-based compounds. The present study investigated the potential thyroidogenicity of 2,2',2″,4-tetrabromo-(TB)-DiPhOBz along with its para-methoxy (MeO)- and hydroxy-(OH)-analogues, using an in vitro competitive protein binding assay with the human thyroid hormone (TH) transport proteins transthyretin (hTTR) and albumin (hALB). This model para-OH-TB-DiPhOBz was found to be capable of competing with thyroxine (T4) for the binding site on hTTR and hALB. In silico analyses were also conducted using a 3D homology model for gull TTR, to predict whether these TB-DiPhOBz-based compounds may also act as ligands for an avian TH transport protein despite evolutionary differences with hTTR. This analysis found all three TB-DiPhOBz analogues to be potential ligands for gull TTR and have similar binding efficacies to THs. Results indicate structure-related differences in binding affinities of these ligands and suggest there is potential for these contaminants to interact with both mammalian and avian thyroid function.

Predicting Nanoscale Dynamics of a Glass-Forming Liquid from Its Macroscopic Bulk Behavior and Vice Versa.

The properties of a molecular liquid confined at the nanometer length scale can be very distinct from the bulk. For that reason, the macro- and the nanoscopic behaviors of glass-forming liquids are regarded as two nonconnected realms, governed by their own rules. Here, we show that the glassy dynamics in molecular liquids confined to nanometer pores might obey the density scaling relation, ργ/T, just like in bulk fluids. Even more surprisingly, the same value of the scaling exponent γ superposes the α-relaxation time measured at different state points in nanoscale confinement and upon increased pressure. We report this remarkable finding for van der Waals liquids tetramethyl-tetraphenyl-trisiloxane (DC704) and polyphenyl ether (5PPE), considered as simple, single-parameter liquids. Demonstrating that the density scaling idea can be fulfilled in both environments opens an exciting possibility to predict the dynamic features of the nanoconfined system close to its glass-transition temperature from the high-pressure studies of the bulk liquid. Likewise, we can describe the viscous liquid dynamics at any given combination of temperature and pressure based on analysis of its behavior in nanopores.

Flow measurements of a polyphenyl ether oil in an elastohydrodynamic contact

A novel methodology, based on the use of phosphorescence imaging, is applied to determine the local through-thickness velocity profile of lubricant in an elastohydrodynamic contact. The technique has spatial and temporal resolutions of 40 μm and 340 μs respectively and thus allows lubricant rheology to be investigated at conditions close to service conditions. The capability of the newly-developed method is verified by examining the flow of 5P4E polyphenyl ether, a lubricant base fluid used in very high temperature applications and is well-known for its high viscosity-pressure coefficient. Experimental results highlight the effect of the contact pressure on the velocity profile of this fluid in lubricated contacts. At low pressures, the velocity profile of 5P4E is close to linear, characteristic of Couette flow. As the local pressure increases, its velocity profile progressively deviates from a Couette profile and shear banding is evident at high pressure.

Sunlight Irradiation of Highly Brominated Polyphenyl Ethers Generates Polybenzofuran Products That Alter Dioxin-responsive mRNA Expression in Chicken Hepatocytes.

We report on two highly brominated polyphenyl ether flame retardants, tetradecabromo-1,4- diphenoxybenzene (TeDB-DiPhOBz) and 2,2',3,3',4,4',5,5',6,6'-decabromodiphenyl ether (BDE-209), that formed photolytic degradation products in tetrahydrofuran (THF)/hexane solvent after 21 days of natural sunlight irradiation (SI). These degradation products of SI-TeDB-DiPhOBz and SI-BDE-209 included the numerous polybrominated homologue groups of polybenzofurans and dibenzofurans, respectively. Formation of similar polybenzofuran and dibenzofuran products was also observed following a 3 month exposure of the solid powder forms of TeDB-DiPhOBz and BDE-209 to natural SI. These resulting degradation product mixtures were administered to chicken embryonic hepatocytes (CEH) to determine effects on mRNA expression levels of 27 dioxin-responsive genes. For the solvent-based SI study, equivalent concentrations of 1 or 25 μM of SI-TeDB-DiPhOBz or 1 or 10 μM of SI-BDE-209 resulted in gene expression profiles that were similar to those of the most potent dioxin-like compound, 2,3,7,8-tetrachlorodibenzo-p-dioxin. In addition, a concentration-dependent induction of CYP1A4 and CYP1A5 mRNA was observed following exposure to SI-TeDB-DiPhOBz and SI-BDE-209. Based on ECthreshold values for CYP1A4/5 mRNA expression, relative potency (ReP) values were 1 × 10(-6) and 1 × 10(-5) for SI-TeDB-DiPhOBz and SI-BDE-209, respectively. The SI TeDB-DiPhOBz and BDE-209 powder degradation product mixture also significantly induced CYP1A4 mRNA levels in CEH. Our findings clearly show that the environmental stability of TeDB-DiPhOBz and BDE-209, and possibly other highly brominated polyphenyl ethers, is of great concern from a dioxin-like degradation products and toxicity perspective.

Development of radiation hard components for ITER blanket remote handling system

The ITER blanket remote handling system (BRHS) will be operated in a high radiation environment (250Gy/h max.) and must stably handle the blanket modules, which weigh 4.5t and are more than 1.5m in length, with a high degree of position and posture accuracy. The reliability of the system can be improved by reviewing the failure events of the system caused by high radiation. A failure mode and effects analysis (FMEA) identified failure modes and determined that lubricants, O-rings, and electric insulation cables were the dominant components affecting radiation hardness. Accordingly, we tried to optimize the lubricants and cables of the AC servo motors by using polyphenyl ether (PPE)-based grease and polyether ether ketone (PEEK), respectively. Materials containing radiation protective agents were also selected for the cable sheaths and O-rings to improve radiation hardness. Gamma ray irradiation tests were performed on these components and as a result, a radiation hardness of 8MGy was achieved for the AC servo motors. On the other hand, to develop the radiation hardness and BRHS compatibility furthermore, the improvement of materials of cable and O ring were performed.

Preparation and Characterization of sPDVB/SPPO Composite Proton Exchange Membrane for Fuel Cell

In this study, a series of composite proton exchange membranes are prepared from sulfonated polydivinyl benzene (sPDVB) microspheres and sulfonated polyphenyl ether (SPPO). The PDVB microsphers and PPO are functionalized by direct sulfonation. The synthesis products are characterized by Fourier Transform Infrared Spectroscopy technique (FT-IR), thermogravimetry analysis (TGA), scanning electron microscope (SEM). The incorporation of sPDVB decreases the water uptake and proton exchange capacity, so the proton conductivity is lower than that of blank SPPO membrane. But the composite membranes still have the excellent conductivity range from 4.88×10-2 to 6.99×10-2 Scm-1.

619 ねじ締結用潤滑剤の潤滑特性に関する基礎的研究

The lubrication performance of polyisobutylene which is used as a lubricant for screw tightening was studied in order to understand the lubrication mechanism during the tightening process. Ball on plate type spinning friction tests were conducted, and three kind of polyisobutylene(PIB-L, M, H) in which the highest viscosity is PIB-H, followed by PIB-M and PIB-L, and polyphenyl ether(5P4E) were used as lubricants in this study. Results at 400 MPa show that the friction coefficient tested in PIB depends on the viscosity, and the coefficient in PIB-H is the highest in the lubricants. It is also shown in results at 600MPa that the friction coefficient in PIB-L, H, 5P4E changes in the range from 0.2 to 0.5 during the test, and the contact area after the test shows large wear. On the other hand, the friction coefficient in PIB-M is lower than that in PIB-L, H, and wear amount in PIB-M is the smallest. These results suggest that the lubrication film formed by PIB-M has an ability to prevent for the direct contact between the surfaces at the condition with high contact pressure.

Methodology and determination of tetradecabromo-1,4-diphenoxybenzene flame retardant and breakdown by-products in sediments from the Laurentian Great Lakes

Tetradecabromo-1,4-diphenoxybenzene (TeDB-DiPhOBz) is a brominated polyphenyl ether flame retardant (FR) that is known to photolytically degrade to produce lower brominated polybrominated-diphenoxybenzenes (PB-DiPhOBzs), which may be precursors to MeO-PB-DiPhOBzs recently reported in the Great Lakes herring gulls eggs. To our knowledge, there are no reports on TeDB-DiPhOBz or other PB-DiPhOBz by-products in any environmental sample. The present study analyzed for the presence of PB-DiPhOBzs (including TeDB-DiPhOBz) and MeO-PB-DiPhOBzs in surficial sediment from sites in Saginaw Bay in western Lake Huron (n=7), and in comparison to southern Lake Huron (open water) (n=5) and Lake Erie (n=3) sediment collected in the summers of 2012 or 2013. To analyze for possible PB-DiPhOBzs (Br14–Br0), the first known analytical method was developed for extraction and cleanup of sediment samples, and analysis by HPLC–atmospheric pressure photoionization (−)-quadrupole time-of-flight-mass spectrometry. The overall recovery efficiency was optimized to on average 33–104% progressing from Br14- to Br10-PB-DiPhOBzs. Br10- to Br14-PB-DiPhOBz detection and quantification limits ranged from 0.05 to 0.15ngg−1 dw and 0.17 to 0.49ngg−1 dw, respectively. Although this is the first report, PB-DiPhOBzs (Br14–Br10) and MeO-PB-DiPhOBzs were not detectable in any sediment sample. This included a site near the mouth of the highly FR-contaminated Saginaw River, near the confined disposal facility (CDF) located in Saginaw Bay at Channel-Shelter Island, which receives dredged sediment from the Saginaw River. Our findings suggest sediments from the presently studied sites in the Great Lakes ecosystem are not a sink for TeDB-DiPhOBz and PB-DiPhOBz by-product contaminants.

Communication: Two measures of isochronal superposition

A liquid obeys isochronal superposition if its dynamics is invariant along the isochrones in the thermodynamic phase diagram (the curves of constant relaxation time). This paper introduces two quantitative measures of isochronal superposition. The measures are used to test the following six liquids for isochronal superposition: 1,2,6 hexanetriol, glycerol, polyphenyl ether, diethyl phthalate, tetramethyl tetraphenyl trisiloxane, and dibutyl phthalate. The latter four van der Waals liquids obey isochronal superposition to a higher degree than the two hydrogen-bonded liquids. This is a prediction of the isomorph theory, and it confirms findings by other groups.