bluuebunny/crossref_metadata_2025_split huggingface dataset:
Poly(aryl ether ketone)s with bromomethyl groups: Synthesis and quaternary amination
Authors: Ma Wenjia , Zhao Chengji , Lin Haidan , Zhang Gang , Na Hui 
Published: February 2011

AbstractA series of bromomethylated poly(arylene ether ketone)s (PAEKs) with different contents of bromine tethered to the benzyl groups were successfully synthesized and characterized in this work. For this purpose, poly(arylene ether ketone) with 3,3′,5,5′‐tetramethyl‐4,4′‐dihydroxybipheny moiety (PAEK‐TM) was prepared by the aromatic nucleophilic polycondensation, and then the PAEK‐TM has benzylic methyl groups that were converted to bromomethyl groups by a radical reaction using N‐bromosuccinimide. Then, the bromomethylbenzyl groups in the membrane was converted to quaternary ammonium moieties in TMPAEK‐NOH. 1H‐NMR measurements were used to characterize and confirm the structures of the resulting PAEK‐x‐BrTM and TMPAEK‐NBr derivatives (x refers to the molar percentage of bromine introduced per repeating units). TGA analysis showed that PAEK‐x‐BrTM exhibited a very low‐decomposition temperature at about 200°C corresponding to the CBr bond cleavage. The hydroxide conductivity of TMPAEK‐NOH membrane was 8 mS cm−1 at room temperature, while the water uptake of TMPAEK‐NOH membrane was 22.3% at 20°C and 32.6% at 60°C. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Morphology, dynamic mechanical, and electrical properties of bio‐based poly(trimethylene terephthalate) blends, part 1: Poly(trimethylene terephthalate)/poly(ether esteramide)/polyethylene glycol 400 bis(2‐ethylhexanoate) blends
Authors: Kobayashi Toshikazu , Wood Barbara A. , Blackman Gregory S. , Takemura Akio 
Published: February 2011

AbstractBio‐based PTT and PTT blends with PEEA of two different ion contents (275 ppm Na and 3515 ppm Na) and PEG 400 bis (2‐ethylhexanoate) were prepared by melt processing. The blends were characterized by differential scanning calorimetry, dynamic mechanical analysis, transmission electron microscopy, and atomic force microscopy. Electro‐static performance was also investigated for those PTT blends since PEEA is known as an ion conductive polymer. Here we confirmed that PEG 400 bis (2‐ethylhexanoate) improves the static decay performance of PTT/PEEA blends. DMA strongly suggests that PEG 400 bis (2‐ethylhexanoate) and PEEA are miscible pairs, and PEG 400 bis (2‐ethylhexanoate) selectively goes into the PEEA phase rather than the PTT phase, which lowers the Tg of PEEA. Besides topographic analysis of morphology and phase separation, tunneling atomic force microscopy was also applied to see if we can observe the surface directly for the static dissipative material. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Study on crystallization kinetics of LDPE filled with CaCO3 of different size and size distribution
Authors: Zhang Jun , Fang Jue , Han Bing , Zhou Ninglin , Wu Juan , Ma Zhen‐Mao , Mo Hong , Shen Jian 
Published: February 2011

AbstractThe thermoplastic filled with the different size distribution fillers was a new method for improving processability of thermoplastic composites. In our former study, we found that the melt torque of low‐density polyethylene (LDPE) composites, which were filled with 30 wt % the effective size distribution CaCO3, evidently decreased. In this article, two sizes of CaCO3, 600 meshes and 2500 meshes, were blended by different proportions and were filled into LDPE matrix with 30 wt %. Crystal process, isothermal crystallization kinetics, and nonisothermal crystallization kinetics of a series of composites were characterized by differential scanning calorimeter (DSC). The results showed that composites filled with the effective size distribution CaCO3 leaded to the lower melting and crystallization temperature, the more wide crystallization temperature area, while their the crystallization rate constant (k) of isothermal crystallization kinetics decreased and their Avrami exponents (n) and crystallization half‐life (t1/2) of isothermal crystallization kinetics increased compared with those of the composites filled with the single size CaCO3. Nonisothermal crystallization kinetics had the similar results. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Novel diphenyl thioether‐bridged binuclear metallocenes of Ti and Zr for synthesis of polyethylene with broad molecular weight distribution
Authors: Nie Yujing , Sun Junquan , Yin Wenxia , Wang Lincai , Shi Zuyun , Schumann Herbert 
Published: February 2011

AbstractTwo diphenyl thioether‐bridged binuclear metallocenes of Ti and Zr, [(C5H5)Cl2MC5H4CH2(p‐C6H4)]2S [M = Ti (1) and Zr (2)], have been synthesized by treating the dilithium salts of the corresponding ligand [(C5H5CH2(p‐C6H4)]2S with two equivalents of C5H5TiCl3 and C5H5ZrCl3(DME), respectively, in toluene at 0°C. Both new complexes have been characterized by 1H‐NMR spectroscopy and elemental analysis. Homogeneous ethylene polymerization using both complexes was performed in the presence of methylaluminoxane (MAO). The influences of molar ratio of [MAO]/[Cat], concentration of the catalysts, time, and temperature have been studied systematically. The catalytic activity of 1 is higher than that of the corresponding oxygen‐bridged catalyst [(C5H5)Cl2TiC5H4CH2(p‐C6H4)]2O. The catalytic activity of 2 is at least two times higher than that of 1 under any tested polymerization conditions. The melting points of polyethylene (PE) produced by 1 and 2 are higher than 130°C, indicating a highly linear and highly crystalline PE. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synergistic effect on crystalline structure of polyvinylidene fluoride nanocomposites with multiwalled carbon nanotube loading by a twin screw extruder
Authors: Kang Dong Jin , Pal Kaushik , Bang Dae Suk , Kim Jin Kuk 
Published: February 2011

AbstractPolyvinylidene fluoride (PVDF)/multiwalled carbon nanotube (MWCNT) composites were prepared by using twin screw extruder at various (0–5 wt %) MWCNT loadings. Field Emission Scanning Electron Microscope (FESEM) micrographs showed a relatively good dispersion and random distribution of MWCNT in PVDF matrix. The physical and dielectric properties increased gradually with the increase in MWCNT content but the thermal stability decreased. The DSC result revealed the increase in crystallinity of the PVDF matrix. Wide angle X‐Ray diffraction (WAXD) result showed a large shoulder at 2θ of 20.78° with increasing in MWCNT content. The experimental percolation threshold for the surface resistance of PVDF/MWCNT composites were estimated and clearly observed at 4 wt % of MWCNT loading. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Morphology of polyurethanes at various length scale: The influence of chain structure
Authors: Mishra Abhinay , Maiti Pralay 
Published: February 2011

AbstractMicro‐structural investigation of polyurethanes (PUs) with different chain structure has been reported. Polarized optical microscopic studies of aliphatic polyurethanes demonstrate the development of micro clusters with increasing hard segment content (HSC) and crystallization. DSC and XRD results support the crystalline and amorphous nature of aliphatic and aromatic PUs, respectively. Self‐assembled biphasic morphology is discernible in aliphatic polyurethane while nanometer size domains are observed in aromatic PUs. The dimension of micro‐domain has been measured by using AFM and established its size as independent of hard segment content. The self‐assembly is greater for higher HSC aliphatic PUs leading to the formation of bigger domain while the meager hydrogen bond formation restricts the domain size of aromatic polyurethanes. Segmented morphology of surface as well as in bulk of aliphatic polyurethanes is evident from SEM and TEM images and grows with increasing HSC. In contrast, homogeneous and amorphous nature has been observed for aromatic PUs. In situ segregation of phases in aliphatic PUs have been captured through light transmittance and optical images which is categorically absent in aromatic polyurethane. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Biodegradable and photocurable multiblock copolymers with shape‐memory properties from poly(ε‐caprolactone) diol, poly(ethylene glycol), and 5‐cinnamoyloxyisophthalic acid
Authors: Nagata Minoru , Inaki Kunihito 
Published: February 2011

AbstractBiodegradable and photocurable multiblock copolymers of various compositions were synthesized by the high‐temperature solution polycondensation of poly(ε‐caprolactone) (PCL) diols of molecular weight (Mn) = 3000 and poly(ethylene glycol)s (PEG) of Mn = 3000 with a dichloride of 5‐cinnamoyloxyisophthalic acid (ICA) as a chain extender, followed by irradiation by a 400 W high‐pressure mercury lamp (λ > 280 nm) to form a network structure. The gel contents increased with photocuring time, reaching a level of over 90% after 10 min for all copolymers without a photoinitiator. The thermal and mechanical properties of the photocured copolymers were examined by DSC and tensile tests. In cyclic thermomechanical tensile tests, the photocured ICA/PCL/PEG copolymer films showed good shape‐memory properties at 37–60°C, with both shape fixity ratio and shape recovery ratio over 90% at a maximum tensile strain of 100–300%. The water absorption of these copolymers and their rate of degradation in a phosphate buffer solution (pH 7.0) at 37°C increased significantly with increasing PEG content. The novel photocured ICA/PCL/PEG multiblock copolymers are potentially useful in biomedical applications. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Thermosensitive soy protein/poly(n‐isopropylacrylamide) interpenetrating polymer network hydrogels for drug controlled release
Authors: Liu Yong , Cui Yingde 
Published: February 2011

AbstractA series of the thermosensitive interpenetrating polymer network hydrogels composed of soy protein and poly(N‐isopropylacrylamide) were successfully prepared. The structure and properties were systematically characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, and differential scanning calorimetry. It was found that the hydrogels had good miscibility and high porosity, and the volume phase transition temperatures of the hydrogels were around 32°C. The release behavior and the release mechanism of a model protein, bovine serum albumin (BSA), were also investigated in detail. The results indicated that the release behavior of BSA had strong temperature dependence and the release percentage of BSA could be controlled by modulating the amount of soy protein or crosslinking agent. The analysis of the release mechanism revealed that the Fickian diffusion controlled release was dominant under the experimental conditions. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011.
Poly (styrene‐n‐butyl acrylate‐methyl methacrylate)/silica nanocomposites prepared by emulsion polymerization
Authors: Rong Qianping , Zhu Aiping , Zhong Tao 
Published: February 2011

AbstractPoly (styrene‐n‐butyl acrylate‐methyl methacrylate) (PSBM)/silica nanocomposite was prepared by emulsion polymerization in the presence of oleic acid surface modified nanosilica. The structure, morphology, size, and size distribution were characterized by Fourier transform infrared (FTIR), transmission electron microscopy (TEM), and dynamics laser scattering. The chemical bond was formed between PSBM and nanosilica revealed by FTIR and TEM studies. The composite particles with an averaged diameter ranging from 30 to 80 nm have the core‐shell structure. The effect of silica content on the glass transition temperature Tg, pyrolyze temperature, and rheological behavior of PSBM composites was systematically investigated. The results indicated that the addition of nanosilica could effectively inhibit chain movement, and improved the pyrolyze temperature of PSBM. The steady viscosity and dynamic modulus were strongly dependent on the content and distribution of nanosilica in PSBM nanocomposites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Monitoring nonisothermal crystallization of thermoplastic polymers using a quartz crystal resonator
Authors: Kim Byoung Chul , Maeda Kouji , Kim Young Han 
Published: February 2011

AbstractA new monitoring device for the nonisothermal crystallization of thermoplastic polymers, polyethylene, polypropylene, polystyrene, and polyamide, is developed utilizing a quartz crystal resonator, and its performance is evaluated by comparing the measurements with the results of DSC thermoanalysis and microscopic observation. The experimental results of four different polymers indicate that the variation of resonant freency of the quartz crystal resonator is a good means to monitor the crystallization process. Though the measurements of melting and crystallization are close to the DSC outcome, more deviation is observed with the new device. The change in crystalline morphology during the crystallization process is also detected from the slope changes of the frequency decrease. In comparison with the microscopic observation of polymer films, it is found that the processes of nucleation and crystal growth in nonisothermal crystallization can be explained with the variation of the resonant frequency of the quartz crystal resonator. In addition, crystallization kinetics is modeled with the Avrami equation. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Hydrolytic degradation of poly(ethylene terephthalate) in a pyrolytic two step process to obtain benzene rich oil
Authors: Grause Guido , Handa Tomohiko , Kameda Tomohito , Mizoguchi Tadaaki , Yoshioka Toshiaki 
Published: February 2011

AbstractPoly(ethylene terephthalate) (PET) was degraded in a two step process to obtain a valuable oil, consisting mainly of benzene. First, PET was hydrolyzed in a steam atmosphere at 450°C, and the resulting terephthalic acid was decarboxylized in the presence of CaO. By separating the two fundamental reactions of this degradation process, the hydrolysis reaction and decarboxylation, the amount of residue was reduced, and the amount of benzene obtained increased. It was found that the best results were obtained at a decarboxylation temperature of 700°C, with a yield of 48% benzene. At lower temperatures, the terephthalic acid was adsorbed at the catalyst without decarboxylation; at higher temperatures, large amounts of char were formed due to pyrolytic reactions. Unlike solvolysis processes, no solvent is used in this process; in effect eliminating the expense of processing waste liquids. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and properties of novel dicyanate with low dielectric and water absorption performance
Authors: Zhang Zhongyun , Yu Ruobing , Wang Fan , Wang Jialiang , Jiao Yangsheng 
Published: February 2011

AbstractThe 1,4‐bis (3,5‐dimethyl‐4‐cyanatobenzyl) benzene (BBZCy) was synthesized successfully by the reaction of 1,4‐bis (3,5‐dimethyl‐4‐hydroxybenzyl)benzene(BBZ) with cyanogen chloride in the presence of triethylamine at −5–0°C. Its structure was confirmed by means of FTIR, elemental analysis, MS, and 1H NMR spectra. The monomer of BBZCy was cured by itself or cured with catalysts to form sym‐triazine structure. Thermal properties of cured BBZCy were studied using DSC, DMA, TMA, and TGA. Compared with the commercial bisphenol A dicyanate resin (BADCy), the cured BBZCy resin exhibited a lower dielectric constant (2.66 at 1 GHz), a lower dissipation factor (0.0054 at 1 GHz), lower water absorption (0.8% at 100 h), less thermal stability, and lower glass transition temperature. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Role of choline formate ionic liquid in the polymerization of vinyl and methacrylic monomers
Authors: Sundar D. Sathish , Vijayaraghavan R. , Subramaniam J. , Surianarayanan M. , Mandal A. B 
Published: February 2011

AbstractPolymerizations of vinyl and methacrylate monomers (2‐hydroxyethyl methacrylate, styrene, and methyl methacrylate) were carried out in a choline formate ionic liquid at room temperature without the addition of peroxide‐based initiators. Choline formate acted as both an initiator and a solvent and produced high‐molecular‐weight polymers. Gel permeation chromatography and electron paramagnetic resonance measurements indicated that the polymerizations predominantly occurred by a free‐radical mechanism. This method of polymerization provides an alternate route to eliminate the use of toxic initiators and solvents. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and Biological Evaluation of 2′‐Oxo‐2,3‐dihydro‐3′H‐ spiro[chromene‐4,5′‐[1,3]oxazolidin]‐3′yl]acetic Acid Derivatives as Aldose Reductase Inhibitors
Authors: Rapposelli Simona , Da Settimo Federico , Digiacomo Maria , La Motta Concettina , Lapucci Annalina , Sartini Stefania , Vanni Michael 
Published: February 2011

AbstractAldose reductase (ARL2) is the first enzyme in the polyol pathway which catalyzes the NADPH‐dependent reduction of glucose to sorbitol. Its involvement on diabetic complications makes this enzyme a challenge therapeutic target widely investigated to limit and/or prevent them. On this basis, a limited series of 4‐spiro‐oxazolidinone‐benzopyran derivatives (1–7) were synthesized to evaluate them as potential ARL2 inhibitors. The activity was determined spectrophotometrically by monitoring the oxidation of NADPH catalyzed by ALR2. Within the series of compounds, the 4‐methoxy derivative 1b showed to be the most active compound, exhibiting inhibitory levels in the submicromolar range. In addition, the activity against the aldehyde reductase isoform (ARL1) was also evaluated. Unlike sorbinil (reference drug) that lack of selectivity towards the two enzyme all the tested compounds resulted to be devoid of ARL1 inhibitory activity (IC50 > 10 µM), thus proving to be selective.
Rituximab treatment induces the expression of genes involved in healing processes in the rheumatoid arthritis synovium
Authors: Gutierrez‐Roelens I. , Galant C. , Theate I. , Lories R. J. , Durez P. , Nzeusseu‐Toukap A. , Van den Eynde B. , Houssiau F. A. , Lauwerys B. R. 
Published: February 2011

AbstractObjectiveRituximab displays therapeutic benefits in the treatment of patients with rheumatoid arthritis (RA) resistant to tumor necrosis factor (TNF) blockade. However, the precise role of B cells in the pathogenesis of RA is still unknown. We undertook this study to investigate the global molecular effects of rituximab in synovial biopsy samples obtained from anti‐TNF–resistant RA patients before and after administration of the drug.MethodsPaired synovial biopsy samples were obtained from the affected knee of anti‐TNF–resistant RA patients before (time 0) and 12 weeks after (time 12) initiation of rituximab therapy. Total RNA was extracted, labeled according to standard Affymetrix procedures, and hybridized on GeneChip HGU133 Plus 2.0 slides. Immunohistochemistry and quantitative real‐time reverse transcriptase–polymerase chain reaction experiments were performed to confirm the differential expression of selected transcripts.ResultsAccording to Student's paired t‐tests, 549 of 54,675 investigated probe sets were differentially expressed between time 0 and time 12. Pathway analysis revealed that genes down‐regulated between time 0 and time 12 were significantly enriched in immunoglobulin genes and genes involved in chemotaxis, leukocyte activation, and immune responses (Gene Ontology annotations). In contrast, genes up‐regulated between time 0 and time 12 were significantly enriched in transcripts involved in cell development (Gene Ontology annotation) and wound healing (Gene Set Enrichment Analysis). At baseline, higher synovial expression of immunoglobulin genes was associated with response to therapy.ConclusionRituximab displays unique effects on global gene expression profiles in the synovial tissue of RA patients. These observations open new perspectives in the understanding of the biologic effects of the drug and in the selection of patients likely to benefit from this therapy.
Self‐Assembly and Aggregate‐Induced Enhanced Emission of Amphiphilic Fluorescence Dyes in Water and in the Solid State
Authors: Hirose Takashi , Higashiguchi Kenji , Matsuda Kenji 
Published: February 2011

Abstract1‐Cyano‐1,2‐bis(biphenyl)ethene (CNBE) derivatives with a hexa(ethylene glycol) group as an amphiphilic side chain were synthesized and the self‐assembling character and fluorescence behavior were investigated. The amphiphilic derivatives showed aggregate‐induced enhanced emission (AIEE) in water and in the solid state. The fluorescence quantum yield increased as the rigidity of the aggregates increased (i.e., in ethyl acetate<in water<in the solid state). As determined from measurements of fluorescence spectra, fluorescence quantum yields, and fluorescence lifetimes, a key factor for the enhanced emission is suppression of the nonradiative decay process arising from restricted molecular motion. Additionally, the difference in the emission rate constant is not negligible and can be used to interpret the difference in fluorescence quantum yield in water and in the solid state.
Facile Preparation of Homo‐ and Hetero‐Dimetallic Complexes with a 4‐Phosphino‐Substituted NHC Ligand. Toward the Design of Multifunctional Catalysts
Authors: Mendoza‐Espinosa Daniel , Donnadieu Bruno , Bertrand Guy 
Published: February 2011

AbstractA series of bimetallic complexes have been synthesized that are supported by a 4‐phosphino‐substituted NHC ligand. The use of this stable ligand reduces the number of synthetic steps and allows for a wide range of metal combinations to be introduced into the complexes.
Stabilization of nonlinear networked probabilistic interval delay systems with sensor random packet dropout
Authors: Zhang Yong , Fang Huajing , Wang Baoxian 
Published: February 2011

AbstractIn this paper, the problem of stabilization for nonlinear networked systems with probabilistic interval delay and sensor random packet dropout is investigated. By employing the information of probabilistic distribution of time‐varying delay and considering random sensor packet dropout with compensation, the nonlinear stochastic delayed system model is established. Based on the obtained model, by choosing an appropriate Lyapunov function and utilizing a new discrete Jensen‐type inequality, sufficient conditions are derived to obtain the relation of the maximum allowable delay bound, delay interval occurrence rate and packet dropout rate to the stochastic stability of nonlinear networked control systems. Two kinds of design procedures for output feedback controller are also presented in terms of solving corresponding linear matrix inequalities. Numerical examples are provided to illustrate the effectiveness and applicability of proposed techniques.Copyright © 2011 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society
Intraseasonal variability in the South American monsoon system
Authors: Ferreira Solange Aragão , Gan Manoel Alonso 
Published: February 2011

AbstractThe active and break periods of the South America monsoon system (SAMS) were determined based on a monsoon rainfall index (MRI) for the three wettest months. The precipitation composite for active cases shows a pattern similar to the average summer rainfall. The wind circulation composite presents a strong northwesterly flow from the western Amazon to southeastern Brazil. During the active (break) periods, an intense (weak) moisture flux convergence occurs over the Amazon basin, southeastern and central‐western Brazil. The intense moisture convergence over these regions during the active periods is a typical feature of the South Atlantic convergence zone (SACZ) system. Copyright © 2011 Royal Meteorological Society
Power calculation for gravitational radiation: oversimplification and the importance of time scale
Authors: Whiting A.B. 
Published: February 2011

AbstractA simplified formula for gravitational‐radiation power is examined. It is shown to give completely erroneous answers in three situations, making it useless even for rough estimates. It is emphasised that short timescales, as well as fast speeds, make classical approximations to relativistic calculations untenable (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)