High Polymeric Materials Research Articles

HM-CFRP ile güçlendirilmiş çelik I kirişlerin eğilme davranışlarının YSA analizi ile incelenmesi

Steel sections used in the bridge, the beam can be renewed or reinforced for systems which have section loss due to corrosion or insufficient sections due to increasing traffic load. The solution is recommended as the sectional replaced or strengthened. Thanks to technological advances with high rigidity high modulus carbon fiber-reinforced polymer (HM-CFRP) materials are produced, and these materials are used again for the high elastic modulus reinforced with steel construction components. Thus, gaining strength in polymer reinforced steel construction elements are provided with the material stiffness and strength. However, experimental studies on the reinforced beams are not economic and monetary aspects of time. The difficulty of experimental cases, numerical models created parametric studies can be conducted. In this study, numerical models validated with experimental work, then tested with parametric study of the YSA. Study of numerical modeling ABAQUS finite element model of care used materials and the geometric nonlinear analysis. When the results obtained from modeling with NNA and FEM are compared, the former has given reliable, fast results for the behavior of RC composite steel I-Section retrofitted or repaired by HM-CFRP.

Preparation and characterization of low density Poly (Imino Imino Ketone) foam

Poly(Imino Ketone) (PIK) is a group of novel high performance polymer material with excellent thermal properties and dissolubility. Aiming at the requirements of inertial confined fusion (ICF) studies on low density polymer foams, we firstly synthesized poly(imino imino ketone) (PIIK) by palladium catalyzed C-N cross-coupling reaction, and successfully prepared the PIIK foam material with a density of 80-300 mg/cm3 by using PIIK as the raw material with thermal-induced phase separation and lyophilization technique. Mercury injection method was used to determine the structure of PIIK foams, and the results indicated that the mean pore diameter was lower than 5 μm and it had relatively high voidage and specific surface area.

Anti-inflammatory activity of polysaccharide from Schizophyllum commune as affected by ultrasonication

Ultrasound treatment was applied to modify the physicochemical properties of an exopolysaccharide from mycelial culture of Schizophyllum commune. Molecular weight (MW) degradation, viscosity and anti-inflammatory property of ultrasonic treated polysaccharide were optimized with response surface methodology. The best ultrasonic parameters were obtained with a three-variable-three-level Box-Behnken design. The optimized conditions for efficient anti-inflammatory activity are initial concentration at 0.4%, ultrasonic power at 600W, and duration of ultrasonic irradiation for 9min. Under these conditions, the nitric oxide inhibition rate was 95±0.03% which agreed closely with the predicted value (96%). Average MW of polysaccharide decreased after ultrasonic treatments. The viscosity of degraded polysaccharide dropped compared with native polysaccharide. The anti-inflammatory activity was improved by ultrasound treatment. The results suggested that ultrasound treatment is an effective approach to decrease the MW of polysaccharide with high anti-inflammatory activity. Ultrasonic treatment is a viable modification technology for high MW polymer materials.

The Synthesis of Styrene-Oligoester Copolymer and Investigation of Their Physico-mechanical Properties

<p>The copolymerization reaction of commercial propylene oxide with glycidylmethacrilate in the presence of BF<sub>3</sub>·O(C<sub>2</sub>H<sub>5</sub>)<sub>2</sub> catalyst have been investigated. The composition and structure of copolymerization products and anchored functional groups have been determined using IR and gel chromatographic methods. The physico-mechanical properties and utility of polyfunctional unsaturated oligoester were investigated. The obtained thermoset product via the reaction of the oligoester with both styrene and oligostyrene obtained from the bottom of column as a waste material during the rectification operation of styrene in the presence of radicalic initiator has a good adhesion capability, hardness and high heat and water resistance. Thus the waste material was converted to the high valuable polymeric material.</p>

Preparation of high thermal stability polysulfone microcapsules containing lubricant oil and its tribological properties of epoxy composites

Polysulfone (PSF) microcapsules containing lubricant oil have been successfully prepared using solvent evaporation method. The results show that lubricant oil was successfully encapsulated and the encapsulation capacity of about 56.0 wt.% was achieved. The uniform microcapsules have nearly spherical shape and quite smooth outer surface. The mean diameter is approximately 156 and 169 μm by using different dispersant solutions. The wall material is porous in structure with wall thickness of about 20 μm. The initial decomposition temperature of PSF is 480 °C. It is higher than traditional poly(urea-formaldehyde) (PUF) and poly(melamine-formaldehyde) (PMF) wall materials with 245 °C and 260 °C initial decomposition temperature, respectively. High thermal stability of PSF microcapsules can be considered as additives in high temperature resistant polymer materials. The frictional coefficient and wear rate of epoxy composites decreased significantly by incorporating microcapsules containing lubricant oil into epoxy. When the concentration of microcapsules was 25 wt.%, the frictional coefficient and specific wear rate were reduced by 2.3 and 18.3 times, respectively, as compared to the neat epoxy.

Hyperbranched Polymers with High Transparency and Inherent High Refractive Index for Application in Organic Light‐Emitting Diodes

Hyperbranched polyvinylsulfides have been prepared through a facile, metal‐free, radical induced “A2+B3” thiol‐yne polymerization of 1,3,5‐tris(naphthalylethynyl) benzene and 1,4‐dithiolbenzene with three different input ratios. The resulting polymers exhibit excellent optical properties like high transparency and very high refractive index (RI) of up to 1.7839, combined with high thermal stability (Td5% up to 420 °C) and excellent solution processability. These properties make them ideal candidates as high RI polymeric materials (HRIP) in connection with light out‐coupling schemes for organic light‐emitting diodes (OLEDs). A series of hyperbranched HRIPs with varying monomer compositions have been compared in their optical properties. Finally, phosphorescent monochrome OLEDs are fabricated on top of HRIP layers to test the compatibility of HRIPs with state‐of‐the‐art OLEDs. The results show that the HRIPs do not deteriorate the performance of the OLEDs while maintaining external quantum efficiencies of over 20% for phosphorescent red OLEDs. These results open a pathway toward alternative, low‐cost, and scalable out‐coupling concepts through refractive index matching of the OLED materials and the HRIPs presented.

キンク損傷を有する高弾性率タイプPBO繊維の疲労強度

In this study, fatigue strength of high-modulus type PBO (Poly-p-Phenylene Benzobisoxazole) fiber with kinking damage was investigated in monofilament fatigue tests. PBO fiber is high polymer material and has the highest tensile strength and tensile modulus of elasticity in any polymeric fiber. Kinking damages was created on surface of virgin fiber by winding bundle fibers to steel rod. Diameter of steel rod was set to 0.625 mm. Average value of compressive strain on surface of fiber determined based on the diameter of steel rod was -1.71 %. Load-controlled fatigue tests were carried out using a sinusoidal load with frequency 10 Hz and stress ratio of R = 0.5, and the load cell capacity was 10 N. It was found that fatigue strength of PBO fiber with kinking damage was lower than that of PBO fiber without kinking damage. Fatigue strength decrease of PBO fiber with kinking damage in a low cycle area was larger than that in a high cycle area.

A Prism-based Polymeric Surface Plasmon Resonance Biochip for Angular and Spectral Modes

A prism-based polymeric biochip (called PPBIO), that allows surface plasmon resonance sensing in both angular and spectral or wavelength interrogation modes, was designed and constructed. It is formed from high quality polymer materials, which uses injection molding method to the high volume manufacture of prisms. Two molds have been manufactured with three and four cavities and a comparison is also presented. Experimental tests were conducted and the results indicate a reduction in the mechanical stresses and birefringence. Eventually, our proposal is a good candidate for point-of-care diagnosis, like is extensively investigated for tropical diseases.

A Rapid LC-HRMS Method for the Determination of Domoic Acid in Urine Using a Self-Assembly Pipette Tip Solid-Phase Extraction.

In this study, we developed a self-assembly pipette tip solid-phase extraction (PTSPE) method using a high molecular weight polymer material (PAX) as the adsorbent for the determination of domoic acid (DA) in human urine samples by liquid chromatography high-resolution mass spectrometry (LC-HRMS) analysis. The PTSPE cartridge, assembled by packing 9.1 mg of PAX as sorbent into a 200 μL pipette tip, showed high adsorption capacity for DA owing to the strong cationic properties of PAX. Compared with conventional SPE, the PTSPE is simple and fast, and shows some advantages in the aspects of less solvent consumption, low cost, the absence of the evaporation step, and short time requirement. All the parameters influencing the extraction efficiency such as pH, the amount of sorbent, the number of aspirating/dispensing cycles, and the type and volume of eluent in PTSPE were carefully investigated and optimized. Under the optimized conditions, the limit of detection (LOD) and limit of quantification (LOQ) values of DA were 0.12 μg/L and 0.37 μg/L respectively. The extraction recoveries of DA from the urine samples spiked at four different concentrations were in a range from 88.4% to 102.5%. The intra- and inter-day precisions varied from 2.1% to 7.6% and from 2.6% to 12.7%, respectively. The accuracy ranged from −1.9% to −7.4%.

Human IgG detection in serum on polymer based Mach-Zehnder interferometric biosensors.

We report a new method for detecting human IgG (hIgG) in serum on integrated-optical Mach-Zehnder interferometer biosensors realized in a high index contrast polymer material system. In the linear range of the sensor (5-200 nM) we observed excellent signal recoveries (95-110%) in buffer and serum samples, which indicate the absence of matrix effects. Signal enhancement was reached by using secondary anti-human IgG antibodies, which bind to immobilized target IgGs and allow detecting concentrations down to 100 pM. This polymer based optical sensor is fully compatible with cost-efficient mass production technologies, which makes it an attractive alternative to inorganic optical sensors. Graphical abstract of the hIgG measured on polymer based photonic sensors using a direct binding assay and a signal enhancement strategy with secondary antibodies.

Investigation on application of basalt materials as reinforcement for flexural elements of concrete bridges

Basalt polymers are rather new materials for civil engineering; therefore, identification of peculiarities and limitations of application of such polymers in concrete structures (particularly bridges) is of vital importance. This paper experimentally investigates deformation behaviour and cracking of flexural elements, which are predominant parameters governing serviceability of the bridges. Unlike a common practice, the present study is not limited by the analysis of concrete beams reinforced with the polymer bars; it also considers effectiveness of basalt fibre reinforced polymer sheets for repairing the beams. The analysis has revealed that a combination of the high strength and elasticity polymer materials governs the effective repair of the beams by significantly increasing (up to 40%) the structural stiffness.

Detection of dissolved gas in oil–insulated electrical apparatus by photoacoustic spectroscopy

One of the most effective and convenient ways to determine the early stages of potential faults in oil-insulated electrical apparatus and to monitor the development is to routinely detect and analyze the concentrations and fluctuations of potential fault gases [1]-[5]. This method has been widely used in power-grid operations and is effective in preventing the occurrence of catastrophic faults. In the past, the technology to detect mixed gas by electrochemical sensors offered effective early warnings of potential faults in electrical apparatus. Today, gas chromatography is widely used to accurately detect the composition of various gases dissolved in oil. Fault development can accurately be diagnosed by using gas chromatography together with various other means such as the Duval Triangle and key gas methods. After extended use, these techniques have been found to have drawbacks, namely, the need to routinely replace or calibrate chromatographic columns and sensors because their properties change with use, and the consumption of calibration and carrier gases with gas chromatography use [6], [7]. Photoacoustic spectroscopy, developed in the 1970s, is a spectral detection and analysis technology derived from a combination of spectroscopy and calorimetry. The method is powerful in physical chemistry research that involves inorganic or organic compounds, semiconductors, metallic materials, and high-polymer materials. It has found widespread application in various disciplines, such as physics, chemistry, biology, medicine, and geology. The major advantages associated with photoacoustic spectroscopy are that it (1) is characterized by high monitoring sensitivity because it directly measures the energy absorbed by gases without background noise; (2) uses easily available air instead of high-purity inert gases as the carrier gas without consuming the to-be-measured gas; (3) does not require chromatographic columns and sensors, which are easily contaminated, undergo aging, and require frequent replacement; (4) does not require a calibration gas, raising the prospect of realizing true maintenance-free operation; and (5) displays a high level of versatility because it even detects the contents of high-concentration gases in the oil tank of on-load tap changers [8]-[12]. Therefore, photoacoustic spectroscopy can greatly enhance the on-line monitoring of electrical system maintenance owing to its high stability, low drift, and maintenance-free features. Considering these technical characteristics, we devised a test platform by combining the technology with the headspace degassing technique. Thus, we investigated the application of photoacoustic spectroscopy to detecting concentrations of gases dissolved in oil-insulated electrical apparatus.

Tailoring the dipole properties in dielectric polymers to realize high energy density with high breakdown strength and low dielectric loss

High energy density polymer materials are desirable for a broad range of modern power electronic systems. Here, we report the development of a new class of polymer dielectrics based on polyurea and polythiourea, which possess high thermal stability. By increasing the dipole density, the dielectric constant of meta-phenylene polyurea and methylene polythiourea can be increased to 5.7, compared with aromatic polyurea and aromatic polythiourea, which have a dielectric constant in the range of 4.1–4.3. The random dipoles with high dipolar moment and amorphous structure of these polyurea and polythiourea based polymers provide strong scattering to the charge carriers, resulting in low losses even at high electric fields. Consequently, this new class of polymers exhibit a linear dielectric response to the highest field measured (>700 MV/m) with a high breakdown strength, achieving high energy density (>13 J/cm3) with high efficiency (>90%).

Hypotheses about the Tools Origin of Textile Materials

As high polymer materials, textile materials are easily to be carbonized and then disappear, so it is almost impossible to study the origin of it from physical evidence. Based on the objective historical facts, through analysis and inference, the paper believed that textile materials, as soft materials, are better than stone tools in the aspects of obtaining, making, functions and uses. Two hypotheses about the origin of textile materials are proposed. The first is that textile materials originate from tools, and the origin time of it is not later than stone tools. The second is that signs and clothing application of textile materials both evolve from its usage as tools, so the origin sequence of textile materials is tools, signs, and clothing.

Manufacturing Process Evolution Method of Neutron Ellipsoidal Mirror Simulation Using Measured Point-Set

Small angle neutron scattering (SANS) analysis using ellipsoidal neutron mirrors are highly demanded for basic researches of high tensile strength steel sheets, proteins and polymer materials. Although the mirror was conventionally assembled from multilayer neutron super mirrors deposited on ground and polished glass segments, it was difficult to align segmented mirrors with high accuracy and it took several months for the grinding and polishing process. An optimized manufacturing process is proposed utilizing optical function evaluation based on measured mirror surface profile. Optical aberration caused by surface form error and misalignment is evaluated by ray-tracing using mirror surface profile measured by non-contact high precision profilometer.

Formation of a Compact Protective Layer by Magnesium Hydroxide Incorporated with a Small Amount of Intumescent Flame Retardant: New Route to High Performance Nonhalogen Flame Retardant TPV

Magnesium hydroxide (MH) and an intumescent flame retardant (IFR) have been incorporated into a thermoplastic vulcanizate (TPV) for the purpose to fabricate halogen-free flame retardant elastomeric materials. Significant synergistic effects of MH and IFR have been observed for the TPV in terms of both flame retardant properties and mechanical performance. The mechanism of the synergistic effects has been investigated. The results indicate that a small amount of IFR accelerates the degradation of the matrix and induces a shrinkage matrix, leading to a compact and unbroken MgO protective layer. Such compact MgO layer on the surface of the material prevents the bulk material from further degradation, and a high flame retardant performance was achieved. Obviously, this novel flame retardant system paves new possibility for the high performance nonhalogen flame retardant polymeric materials and should also be applied to other polymers.

The Study on Infrared Radiation Characteristics of Textile Materials

Textile materials almost belong to high polymer material,which have three kinds of phenomena below: reflection, projection and absorption. Due to the particularity of fiber structure, radiation incident to the fiber radiation occurs the multiple internal reflection as well as the transmission and absorption of part of radiation.

A Simulation Study on OH-Containing Polyimide (HPI) and Thermally Rearranged Polybenzoxazoles (TR-PBO): Relationship between Gas Transport Properties and Free Volume Morphology

Recently, high free volume polymer materials have been regarded as high potential candidates for gas transport/separation membranes, since the amount of free volume in polymeric membrane can improve the diffusivity and solubility of gas molecules. In this study, we focused on how local changes in polymer structure can affect the performance of a membrane at the molecular level. The transport behavior was theoretically analyzed, and then the differences in the amount and morphology of free volume were characterized. Finally, we suggested how the "evolution of microcavities" affects the gas transport properties of hydroxyl-containing polyimide (HPI) and thermally rearranged (TR) polymers. In particular, using image analysis, we intuitively demonstrate the morphological difference between HPI and TR polymers that have been indirectly explained by experimental analyses using a wide-angle X-ray diffractometer (WAXD) and positron annihilation laser spectroscopy (PALS). Solubility results using the grand canonical Monte Carlo (GCMC) method showed marginal improvement in thermally rearranged polybenzoxazoles (TR-PBOs) from its precursor HPI, which is in good agreement with the experimental tendency. Moreover, higher diffusivities but lower selectivities of TR-PBO models compared with those of HPI models were observed, as reported experimentally. The difference in gas transport abilities between HPIs and TR-PBOs originates from the difference in their diffusion behavior, and this is strongly related to the free volume amount and morphology of polymeric materials. In addition to the higher amount of total free volume in TR-PBO, our image analysis revealed that TR-PBO has a higher amount of interconnected "hourglass-shaped free volume elements", which consist of larger and more elongated cavities with bottlenecks than the HPI model. In particular, the bottleneck diameters in the TR-PBO models are wider than those in the HPI models, enabling the larger gas molecules to diffuse through the cavities faster. However, the narrower and smaller bottleneck diameters in the HPI model can induce better selectivity for large gas molecules.

B14 高速非接触加工機上計測によるマルチセグメント中性子反射光学素子の形状測定(OS11 超精密加工)

Neutron analysis technique using neutron focusing mirrors are highly demanded for basic researches of high tensile strength steel sheets, proteins and polymer materials. Although we proposed a new fabricating method of multi-segmented neutron focusing mirrors using metal substrates, it was difficult to measure surface profile precisely. This paper reports a development of non-contact fast speed on-machine measurement probe in order to measure the fabricated mirror profile and results of the profile measurement of super mirrors deposited on polished substrates.

Lithography Process Simulations using OCTA -Application to Development and DSA

In 2002, the simulation software system for high functional polymeric material OCTA is released. OCTA is the general purpose simulator and each multi-scale-level simulation can be easily done. Recently, we have applied our OCTA system to the problems of lithography. In this paper we discuss the applicability of OCTA system to the simulations for lithography. Two kinds of applicability are discussed. One is the development and the rinse process simulations, and another is the directed self assembly simulation. In the former study, LER can be discussed using OCTA simulation. In the latter study, many kinds of coarse-grained models can be applicable for the DSA simulation using OCTA. These wide applicability are discussed in this paper.