Fluorine Resin Research Articles

Study of carbon nano-materials through the defluorination method from fluorine resin

Study of carbon nano-materials through the defluorination method from fluorine resin

Investigation of PEFC Characteristics on Four-Layer Electrode Catalyst at 50.DEG.C. or Lower

Water management of the catalyst layer in a polymer electrolyte membrane fuel cell was improved by focusing on the three-phase boundary. To fabricate the cathode catalyst layer, carbon-support with catalyst and fluorine resin were mixed and heat-treated at the melting temperature of fluorine resin. The transmission electron microscopy images of this electrode catalyst showed that the surfaces of the catalyst particle and of the carbon-support were partly coated by thin film of melted fluorine resin. Ionomer electrolyte material was added to this electrode catalyst, and an electrode catalyst with a four-layer structure was fabricated. The durability at 50°C of a single cell using the four-layer electrode catalyst as the cathode was examined. The deterioration rate was lower than that using the conventional three-layer electrode catalyst. In addition, a load change test at 50°C, an OCV test at 50°C, and a durability test at room temperature gave good results.

Study of carbon nano-materials through the defluorination method from fluorine resin

Study of carbon nano-materials through the defluorination method from fluorine resin

Molecular dynamics simulations of RDX and RDX-based plastic-bonded explosives

Molecular dynamics simulations have been performed to investigate well-known energetic material cyclotrimethylene trinitramine (RDX) crystal and RDX-based plastic-bonded explosives (PBXs) with four typical fluorine-polymers, polyvinylidenedifluoride (PVDF), polychlorotri-fluoroethylene (PCTFE), fluorine rubber (F 2311), and fluorine resin (F 2314). The elastic coefficients, mechanical properties, binding energies, and detonation performances are obtained for the RDX crystal and RDX-based PBXs. The results indicate that the mechanical properties of RDX can be effectively improved by blending with a small amount of fluorine polymers and the overall effect of fluorine polymers on the mechanical properties of the PBXs along three crystalline surfaces is (0 0 1) > (0 1 0) ≈ (1 0 0) and PVDF is regarded to best improve the mechanical properties of the PBXs on three surfaces. The order of the improvement in the ductibility made by the fluorine polymers on different surfaces is (0 0 1) ≈ (0 1 0) > (1 0 0). The average binding energies between different RDX crystalline surfaces and different polymer binders are obtained, and the sequence of the binding energies of the PBXs with the four fluorine polymers on the three different surfaces is varied. Among the polymer binders, PVDF is considered as best one for RDX-based PBXs. The detonation performances of the PBXs decrease in comparison with the pure crystal but are superior to those of TNT.

Degradation of cationic red X-GRL by electrochemical oxidation on modified PbO 2 electrode

This work investigated the degradation of an azo dye, cationic red X-GRL, by electrochemical oxidation on a novel PbO 2 anode modified by fluorine resin. The influences of treatment time, electrolyte concentration, current density, temperature and initial dye concentration on the color and COD removal were critically examined. This process showed a high current efficiency and competitive energy consumption for effective treatment of dye wastewater containing a certain salt content. In the investigated electrolyte concentrations, high salt content exhibited insignificant promotion on the color and COD removal but favored the decrease of energy consumption. During treatment, the current efficiency decreased but the energy consumption increased with treatment time; thus, this method was more suitable for the pretreatment of high-concentrated azo dye wastewater. Based on the degradation intermediates identification, a simplified degradation pathway for cationic red X-GRL was proposed.

Barrier and self‐healing abilities of corrosion protective polymer coatings and metal powders for aluminum alloys

AbstractSeveral types of coatings, designed to improve the resistance of aluminum alloys to corrosion in seawater, were examined. A coating with a thickness of approximately 30 μm was applied to the surface of aluminum alloy 3003, and after creating an artificial defect by means of a knife‐edge, a corrosion test was carried out in 3% NaCl solution at a temperature of 70°C and pH 1.5. The test results showed that a fluorine resin and sol‐gel coatings both had excellent barrier abilities. The fluorine resin coating had self‐healing abilities, and this was improved by the addition of a metal powder.

Molecular Dynamics Simulations of trans-1,4,5,8-Tetranitro-1,4,5,8-tetraazadecalin-Based Polymer-Bonded Explosives

Molecular dynamics has been applied to investigate the low-sensitivity explosive TNAD (trans-1,4,5,8-tetranitro-1,4,5,8-tetraazadecalin)-based polymer-bonded explosives (PBXs) with four typical fluorine polymers, PVDF (polyvinylidenedifluoride), PCTFE (polychlorotrifluoroethylene), F(2311) (fluorine rubber), and F(2314) (fluorine resin). The elastic constants, mechanical properties (tensile modulus, bulk modulus, shear modulus, and Poission ratio), binding energies, and detonation performances are first reported for the TNAD-based PBXs. The results show that the mechanical properties of TNAD can be effectively improved by the addition of small amounts of fluorine polymers, and the overall effect of fluorine polymers on the mechanical properties of the PBXs along three crystalline surfaces is (001) > (010) > (100). On each crystal surface, improvement in the ductibility made by the fluorine polymers changes approximately in the sequence of PVDF > F(2311) > F(2314) > PCTFE. The binding energies between different TNAD crystalline surfaces and different polymer binders with the same chain segment or mass fraction both decrease in the order of (010) > (100) > (001). The binding properties of the polymers with the same chain segment on each crystal surface of TNAD increase as PVDF < F(2311) < F(2314) < PCTFE, while those of different polymers in the same content decrease in the sequence of PVDF > F(2311) > F(2314) > PCTFE. The detonation performances of the PBXs decrease in comparison with the pure crystal, but they are superior to those of TNT.

ICONE15-10631 PIV MEASUREMENT OF THE COMPLEX AND TRANSIENT CROSS-FLOW OVER A CIRCULAR CYLINDER

This paper describe about measurement for the complex and transient cross-flow over a circular cylinder with the dynamic (time resolved) PIV (particle image velocimetry) techniques. The experiment was carried out water flow tunnel with a working section of 50x50 mm, at the Reynords number 6.7 x 10^3 to 2.7 x 10^4. This circular cylinder constructed with MEXFLON resin, the end of circular cylinder is rigidly supported and the other is free. The MEXFLON is fluorine resin; its refractive index is almost same as the water with high transparency. Very high speed water flow among the test section had been clearly visualized and captured by high speed camera. The fluctuations of the flow structure also are clearly obtained with high spatial and high temporal resolution, 512x512pixel with 10,000fps. It corresponds to set up number of thousands LDV array at the test section. Consequently, we found there are asynchronous vibration between parallel-ward and perpendicular-ward to main flow.

Surface Treatment of Poly(tetrafluoroethylene) and Perfluoroethylene-propylene by Radiation Grafting

Poly(tetrafluoroethylene) (PTFE) and perfluoroethylene-propylene (PFEP) have many desirable properties for application to electronic devices, such as low dielectric constant and loss tangent. However, the weak adhesion of the polymer to various metals, associated with the chemical inertness of the fluorine resin surface, fails to satisfy many of the industry requirements. Surface treatment of PTFE and PFEP by radiation-induced graft polymerization was carried out to improve the adhesion. Peel adhesion strengths of 10.3 and 14.5 N/cm were attained for PTFE/Cu and PFEP/Cu, respectively by the treatment. In addition, the dielectric function of grafted PTFE and grafted PFEP remained almost unchanged after the graft polymerization.

Molecular Dynamics Simulations for Pure ε-CL-20 and ε-CL-20-Based PBXs

Molecular dynamics has been employed to simulate the well-known high energy density compound epsilon-CL-20 (hexanitrohexaazaisowurtzitane) crystal and 12 epsilon-CL-20-based PBXs (polymer bonded explosives) with four kinds of typical fluorine polymers, i.e., polyvinylidenedifluoride, polychlorotrifluoroethylene, fluorine rubber (F(2311)), and fluorine resin (F(2314)) individually. The elastic coefficients, isotropic mechanical properties (tensile moduli, bulk moduli, shear moduli, and poission's ratios), and bonding energy are first reported for epsilon-CL-20 crystal and epsilon-CL-20-based polymer bonded explosives (PBXs). The mechanical properties of epsilon-CL-20 can be effectively improved by blending with a small amount of fluorine polymers, and the whole effect of the adding fluorine polymers to improve mechanical properties of PBXs along the three crystalline surfaces of epsilon-CL-20 is found to be (100) approximately (001) > (010). The interaction between each of the crystalline surfaces and each of the fluorine polymers is different, and the ordering of binding energy for the three surfaces is (001) > (100) > (010); F(2314) always has the strongest binding ability with the three different surfaces. F(2314) can best improve the ductibility and tenacity of PBX when it is positioned on epsilon-CL-20 (001) crystal surface. The calculations on detonation performances for pure epsilon-CL-20 crystal and the four epsilon-CL-20-based PBXs show that adding a small amount of fluorine polymer into pure epsilon-CL-20 will lower detonation performance, but each detonation parameter of the obtained PBXs is still excellent.

Molecular dynamics simulation of mechanical properties of TATB/fluorine-polymer PBXs along different surfaces

The mechanical properties of PBXs composed of the well-known insensitive explosive TATB (1,3,5-Triamino-2,4,6-trinitrobenzene) crystal and four kinds of typical fluorine-polymers, i.e. poly (vinylidene difluoride) (PVDF), polychlorotrifluoroethylene (PCTFE), fluorine rubber (F 2311 ) and fluorine resin (F2314) individually, have been simulated by molecular dynamics (MD) method. The results show that the mechanical properties of TATB can be effectively improved by blending with a small amount of fluorine-polymers. Different mechanical properties of PBXs are obtained by putting fluorine-polymer binders parallel to different crystalline surfaces. The whole effect of im-proving mechanical properties is found to be (010)≈(100)>(001).

Long Life Modified Lead Dioxide Anode for Organic Wastewater Treatment: Electrochemical Characteristics and Degradation Mechanism

Recent studies have shown that the lack of ideal anodes with both good activity and stability is still one of the critical problems in electrochemical oxidation for organic wastewater treatment. The electrochemical properties, the activity and stability for anodic oxidation of various phenolic compounds, and the degradation mechanism on a novel beta-PbO2 electrode modified with fluorine resin were investigated. The anode life after modification was greatly improved to be more than 10 yr in common electrochemical current conditions. Such an anode was effective for partial degradation of phenolic compounds, but selective because reactive activities were varied with different substituents. Characterized by SEM and XRD, the crystal form of the anode was verified to be mainly beta-PbO2, and it hardly changed when used for p-nitrophenol degradation for around 320 h although there existed slow electrode corrosion. The active species generated during anodic oxidation were determined to be mainly hydroxyl radical and little ozone. The reactions between hydroxyl radical and phenolic compounds were proved to be electrophilic reactions, based on which a general electrochemical degradation mechanism for aromatic compounds was proposed. In general, such a novel anode has a good performance for organics degradation with perfect electrode life, showing potential for environmental application.

A demonstration study on a closed-cycle hydrogen production by the thermochemical water-splitting iodine–sulfur process

Japan Atomic Energy Research Institute (JAERI) has been conducting R&D on thermochemical hydrogen production using the water-splitting iodine–sulfur process, as part of the research programs striving to utilize heat from a high temperature gas-cooled reactor (HTGR). The R&D is currently at the bench-scale stage and covers several fields including the evaluation of structural materials in corrosion environments, the improvement in thermal efficiency and the techniques for an operation in a closed-loop continuous hydrogen production. Preliminary experimental examinations were carried out to investigate compositions of the solutions for the Bunsen reaction, on which the operation is based. An experimental facility made of glass and fluorine resin for a closed-loop continuous hydrogen production has been operated. In the experiment, hydrogen production at the rate of 32 l/h for 20 h was successfully accomplished. Feasibility of the operating stability was almost demonstrated. Hereafter, automation of the operation to maintain the process in a stable state is one of the challenges.

高温ガス炉を利用した熱化学水素製造法ISプロセスの研究 : 連続水素製造試験(FR5 水素・燃料電池)

Thermochemical hydrogen production cycle named IS (Iodine Sulfur) process is a prospective candidate for superior hydrogen production methods so that heats supplied by High Temperature Gas-cooled Reactor (HTGR) are able to be consumed for thermal driving loads. Japan Atomic Energy Research Institute has been conducting R&D on the IS process as part of the research programs striving to utilize heat from HTGR. The R&D is currently at the laboratory stage and covers several fields including the evaluation of structural materials in corrosion environments, the improvement in thermal efficiency and the techniques for a operation in a closed-loop continuous hydrogen production. The techniques are essential for the development of such a closed-cycle chemical process. An experimental apparatus made of glass and fluorine resin for closed-loop continuous hydrogen production was operated. In the experiment, hydrogen production at the rate of 32 liters per hour for 20 hours was successfully accomplished. Feasibility of the operating stability was almost demonstrated.

Synergetic effects of anodic–cathodic electrocatalysis for phenol degradation in the presence of iron(II)

A novel electrocatalysis method for phenol degradation was described using a beta-PbO2 anode modified with fluorine resin and a Ni-Cr-Ti alloy cathode. In case of air sparging at the cathodic zone, the techniques of anodic-cathodic electrocatalysis (ACEC) and ferrous ion catalyzed anodic-cathodic electrocatalysis (FACEC) in the presence of iron(II) were developed. Both of ACEC and FACEC were more effective than anodic electrocatalysis (AEC). The percentage of phenol eliminated by FACEC could increase by nearly 30% compared with that of AEC, and the current efficiency could reach to 70%. Important operating factors such as ferrous ion concentration, air-sparging rate and applied current were investigated and it was found that such beneficial effects could be achieved at a suitable current and ratio of the concentration of ferrous ion to the air sparged. The mechanism of phenol degradation is proposed to be the generation of hydroxyl radicals concerned with the two electrodes. Results also indicated that the process provided an efficient way to regenerate ferrous ion compared with the conventional Fenton's system.

Electrocatalysis method for wastewater treatment using a novel beta-lead dioxide anode

A novel β PbO 2 anode modified with fluorine resin was developed for typical pollutant electrocatalytic degradation and wastewater treatment. Various operating parameters such as applied voltage (3.5-10.5 V), pH (2-6), salinity of the electrolyte (0.5-2 g/L K 2SO 4) and initial phenol concentration (100-400 mg/L) were investigated to explore the electrocatalytic ability of the anode by taking phenol as sample. A preliminary study on dyeing wastewater treatment by this method indicated that the biodegradability could be increased to suit subsequent biological treatment. The stability of the anode has been proved to be high against acidity. The anode showed promising application for treatment of wastewater, especially of high salinity and high acidity wastewater.

Partial degradation of phenol by advanced electrochemical oxidation process.

The partial electrocatalytic degradation of phenol to organic acids has been investigated using an undivided electrolytic reactor with a beta-PbO2 anode containing fluorine resin. It was found that the decrease of benzoquinone (BQ) formed during phenol degradation and the acceleration of the process from phenol to organic acids are possible under an optimized operating condition. A possible pathway for phenol degradation was proposed, and a mathematical model for phenol and BQ evolution was developed. Operating parameters such as initial pH, current density, and temperature of the reaction were found to greatly impact the degradation rate of the phenol and even the pathway. Higher removal rate of phenol and BQ can be achieved at an appropriate temperature and higher current density in acidic medium preferably at pH 4. Under these conditions, phenol would be more likely degraded in the pathway from phenol to organic acids rather than through the BQ. When phenol is completely removed, the toxicity of the wastewater would be lessened suitable for biological process treatment. Accounting for the decrease of instantaneous current efficiency (ICE) during degradation, partial degradation would be highly economical for wastewater treatment, which would be an alternative process in practical application.

Development of a soft denture liner (dough-type) using a fluoroethylene copolymer

We have previously made improvements relating to a denture base lined with soft fluorine resin. This lining material (Kurepeet, Kureha Co.) had qualities of extremely small absorptivity in water, an excellent adhesiveness to the denture base, and long stability in use. This material, however, was not simple in way of use in comparison with the ordinary commercial materials and also had some problems in flexibility.For solving this defect, we have proposed a method, in which soft fluorine resin is mixed and kneaded well with a fluorine-containg oligomer. The new material simplifys the lining method, because it has a fluidity in the stage of flasking. Also, at the stage where the lining work has been completed, this material will have an ideal hardness with an elasticity.

フッ素樹脂含有複合めっき

フッ素樹脂含有複合めっき

Automatic assay of urinary protein using Coomassie Brilliant Blue G-250

An automatic method for the protein assay using Coomassie Brilliant Blue G-250 was developed and applied to the assay of urinary proteins. In developing the automatic system, the adhesion of protein-bound dye to the walls of the flow cell and tubes was found to be the most troublesome problem, by which the baseline was shifted upwardly to give positive errors. For the purpose of preventing such adhesion, the concentration of CBB was reduced to half of that used in the manual method, glass tubes and glass coils were changed to those made of Kel-F material, and the flow cell was coated with fluorine resin. As a result, the staining with protein-bound dye was nearly completely eliminated. The final system showed satisfactory ability in performance, namely, the value of a coefficient variation for the reproducibility within run was 1.3%, that for the carry over was 0–1.1%, and the recovery was 98.8%. The calibration curve was linear in a range of 0–1000 μg/ml, and 80 samples could be processed in 1 h. Thus, the present method may serve as an efficient automatic protein analyzer for routine clinical tests of urine samples.