bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of calcium carbonate and silicone elastomer in a flame retardant system based on ethylene–acrylate copolymer, chalk and silicone elastomer and its effect on flame retardant properties
Authors: Hermansson Anna , Hjertberg Thomas , Sultan Bernt‐Åke 
Published: February 2006

AbstractA combination of microscopy studies (SEM, ESEM/EDX, and TEM/EDX) is proven to be useful in locating chalk particles and silicone elastomer in a flame retardant system based on ethylene–acrylate copolymer, chalk, and silicone elastomer. The dispersion of the two additives was also obtained. The chalk particles were visually observed (at a certain degree of magnification), and the silicone elastomer was detected using characteristic X‐ray mapping and line scans. The analysis provided a good contrast between chalk particles and silicone elastomer in the surrounding polymer matrix. It is shown that dispersion of the additives depends on the mixing conditions, where tougher mixing conditions improve dispersion. A discussion is given on how dispersion correlates with the flame retardant properties of this system. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2085–2095, 2006
Preparation and characterization of polyvinyl alcohol based biomaterials: Water sorption and in vitro blood compatibility study
Authors: Mishra Shefali , Bajpai R. , Katare R. , Bajpai A. K. 
Published: February 2006

AbstractSemi‐interpenetrating polymer networks (semi‐IPNs) based on polyvinyl alcohol (PVA) and crosslinked polyacrylamide (PAM) were prepared by redox polymerization and further characterized by FTIR, ESEM, and XRD techniques. The semi‐IPNs of varying compositions were investigated for their water sorption behavior, and the network parameters like average molecular weight between crosslinks (MC) and crosslink density were evaluated from water imbibition measurements. The semi‐IPNs were also judged for their in vitro blood compatibility by blood clot formation and percent hemolysis test. It was noticed that the chemical architecture exert a profound effect on the over all performance of the biomaterials. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2402–2408, 2006
Solution and solid‐state blend compatibility of poly(vinyl alcohol) and poly(methyl methacrylate)
Authors: Adoor S. G. , Manjeshwar L. S. , Rao K. S. V. Krishna , Naidu B. V. K. , Aminabhavi T. M. 
Published: February 2006

AbstractThe blend miscibility of poly(vinyl alcohol) and poly(methyl methacrylate) in N,N′‐dimethylformamide solution was investigated by viscosity, density, ultrasonic velocity, refractive index, and UV and fluorescence spectra studies. Differential scanning calorimetry and scanning electron microscopy were used to confirm the blend miscibility in the solid state. Blends were compatible when the concentration of poly(vinyl alcohol) was greater than 60 wt %. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2415–2421, 2006
Viscosity behavior of hydroxylated and acetoacetylated polyesters
Authors: Narayan Ramanuj , Chattopadhyay D. K. , Raju K. V. S. N. , Mallikarjuna N. N. , Jawalkar Sheetal S. , Aminabhavi Tejraj M. 
Published: February 2006

AbstractViscosity studies on polyester polymers are important for governing their processing characteristics before their industrial application. In this study, the viscosity properties of hydroxylated polyesters with different diols and partially acetoacetylated polyesters with different amounts of ethyl acetoacetate were examined. The melt viscosities of these polymers were measured with different shear rates and at varying temperatures. The results were analyzed with the Williams–Landel–Ferry equation. In high‐solid‐coatings applications, an understanding about the surface properties and thermodynamic quantities, such as cohesive energy density, the solubility parameter, and the Flory–Huggins interaction parameter, are important. To evaluate these quantities, an atomistic simulation methodology based on Accelrys software was used, which provided insights into the structures of these compounds for further applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2422–2435, 2006
Effects of annealing on morphology of polymer/polymer (PS/PMMA) blend; a fluorescence study
Authors: Uğur şaziye , Pekcan önder 
Published: February 2006

AbstractSteady state fluorescence (SSF) technique conjunction with optical microscopy were used to study the morphology of polystyrene (PS)/poly(methyl methacrylate) (PMMA) blend upon annealing above glass transition in elevated time intervals. The PS/PMMA blends were prepared from dissolution of pyrene (P) and naphthalene (N) labeled PS and PMMA particles, respectively. Monte Carlo simulations were performed to model the N and P fluorescence intensities (IN and IP), using photon diffusion theory. Number of N and P photons (NN and NP) emerging from the front surface of the blend are calculated when only N is excited, where NP photons are combined of photons from radiative (NPR) and nonradiative (NPNR) energy transfer processes. Optical microscopy images were taken at each annealing step to support our findings from fluorescence measurements. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2104–2110, 2006
Synthesis and characterization of graft copolymer (guar gum–g–N‐vinyl‐2‐pyrrolidone) and investigation of metal ion sorption and swelling behavior
Authors: Srivastava Arti , Behari Kunj 
Published: February 2006

AbstractGraft copolymer of N‐vinyl‐2‐pyrrolidone with guar gum was synthesized and its reaction conditions were optimized for better yield using potassium peroxymonosulfate (PMS) and glycolic acid (GA) as a redox initiator. The effect of PMS, GA, hydrogen ions, guar gum, and N‐vinyl‐2‐pyrrolidone (NVP) along with reaction time and temperature were studied by determining the grafting parameters: grafting ratio, efficiency, conversion, add‐on, homopolymer, and rate of grafting. It was observed that the maximum yield occurred at with a time of 120 min at a temperature of 45°C and a guar gum concentration of 0.4 g/L concentration. The graft copolymer was characterized by infrared spectroscopy and thermal analysis. The activation energy for the grafted and ungrafted gum was calculated. It was observed that the graft copolymer was thermally more stable than the pure gum. The swelling and metal ion sorption behavior of guar gum and guar gum‐g‐N‐vinyl‐2‐pyrrolidone also were studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2480–2489, 2006
Preparation of poly(4‐methyl‐1‐pentene) asymmetric or microporous hollow‐fiber membranes by melt‐spun and cold‐stretch method
Authors: Wang Jianli , Xu Zhikang , Xu Youyi 
Published: February 2006

AbstractPoly(4‐methyl‐1‐pentene) (PMP) hollow fibers were prepared and fabricated into gas separation or microporous membranes by the melt‐spun and cold‐stretched method. PMP resin was melt‐extruded into hollow fibers with cold air as the cooling medium. The effects of take‐up speed and thermotreatment on the mechanical behavior and morphology of the fibers were investigated. Scanning electronic microscope (SEM) photos were used to reveal the geometric structure of the section and surface of the hollow fibers. It was found that the original fiber had an asymmetric structure. A “sandwich” mode was used to describe the formation of this special fine structure. And a series of PMP hollow‐fiber membranes were prepared by subsequent drawing, and it was found that there was a “skin–core” structure on the cross section of these hollow‐fiber membranes. Asymmetric or microporous PMP hollow‐fiber membranes could be obtained by controlling posttreatment conditions. The morphology of these membranes were characterized by SEM, and the gas (oxygen, nitrogen, and carbon dioxide) permeation properties of the membranes was measured. The results indicate that the annealing time of the original fiber and the stretching ratio were the key factors influencing the structure of the resulting membrane. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2131–2141, 2006
Preparation of nanometer‐sized poly(methacrylic acid) particles in water‐in‐oil microemulsions
Authors: Zhang Qiuyu , Bao Xujin , Lin Mian , Hourston Douglas J. 
Published: February 2006

AbstractA water‐in‐oil microemulsion, water‐in‐cyclohexane stabilized by poly(ethylene glycol) tert‐octylphenyl, was developed to prepare poly(methacrylic acid) (PMAA) particles. Up to 100% conversion of the amphiphilic monomer, methacrylic acid (MAA), which could not be converted to the polymer efficiently in a dioctylsulfosuccinate sodium salt/toluene microemulsion, was achieved. The viscosity‐average molecular weight of the PMAA prepared was 1.45 × 105 g/mol. The effects of some polymerization parameters, including the reaction temperature and the concentrations of the initiator and the monomer, on the polymerization of MAA were investigated. The results showed that the polymerization rate of MAA was slower than that of acrylamide in the microemulsions reported in the literature. The degree of conversion increased with the initiator concentration, reaction temperature, and monomer concentration. However, the stable microemulsions became turbid during the polymerization when the reaction temperature was at 70°C or at a high monomer concentration (40 wt %) The synthesized PMAA particles were spherical and had diameters in the range of ∼50 nm. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2497–2503, 2006
Thermal conductivity of ramie fiber drawn in water in low temperature
Authors: Yamanaka Atsuhiko , Abe Shunzo , Tsutsumi Masayuki , Kitagawa Tooru , Fujishiro Hiroyuki , Ema Kimiko , Izumi Yoshinobu , Nishijima Shigehiro 
Published: February 2006

AbstractTo understand the effect of extension of molecular chain in amorphous region in polymer fibers to thermal conductivity, the thermal conductivity, tensile modulus and crystal orientation angle of ramie fibers and those drawn by the stress of 17.4 kg/mm2 (water treatment) in the water were investigated. The tensile modulus of ramie fiber in fiber direction increased from 61 to 130 GPa by drawing in the water. The crystal orientation angles of ramie fiber with and without water treatment were measured by X‐ray diffraction. The orientation degrees of ramie fibers without and with water treatment were estimated as 92.9 and 93.6%, respectively. Therefore, the tensile modulus increases two times as that of blank ramie by water treatment although crystal orientation angle does not change distinctly. The increasing of tensile modulus of ramie fiber by water treatment was explained by extension of the molecular chains in the amorphous region. Thermal conductivities of ramie fibers with and without water treatment were measured in the fiber direction in the temperature range from 10 to 150 K. Thermal conductivity of ramie fiber in the fiber direction increased by water treatment. The increasing ratio of thermal conductivity by water treatment agreed to that of sound velocity induced by increasing tensile modulus. Those results suggest that thermal conductivity of polymer fiber increase by the extension of molecular chains in the amorphous region. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2196–2202, 2006
Environmental durability of banana‐fiber‐reinforced phenol formaldehyde composites
Authors: Joseph Seena , Oommen Z. , Thomas Sabu 
Published: February 2006

AbstractWe explored the environmental aging behavior of banana‐fiber‐reinforced phenol formaldehyde (PF) composites. The composites were subjected to water aging, thermal aging, soil burial, and outdoor weathering. The effects of chemical modification and hybridization with glass fibers on the degradability of the composites in different environments were analyzed. The extent of degradation was measured by changes in the weight and tensile properties after aging. Absorbed water increased the weight of water‐aged composites, and chemical treatments and hybridization decreased water absorption. The tensile strength and modulus of the banana/PF composites were increased by water aging, whereas the strength and modulus of the glass/PF composites were decreased by water aging. As the glass‐fiber loading was increased in the hybrid composites, the increase in strength by water aging was reduced, and at higher glass‐fiber loadings, a decrease in strength was observed. The tensile properties of the composites were increased by oven aging. The percentage weight loss was higher for soil‐aged samples than for samples weathered outdoors. The weight loss and tensile strength of the glass/PF composites and banana/glass/hybrid/PF composites were much lower than those of the banana/PF composites. Silane treatment, NaOH treatment, and acetylation improved the resistance of the banana/PF composites on outdoor exposure and soil burial. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2521–2531, 2006
Optimizing multiple qualities in as‐spun polypropylene yarn by neural networks and genetic algorithms
Authors: Huang Chang‐Chiun , Tang Tsann‐Tay 
Published: February 2006

AbstractThis investigation considers a quantitative procedure for determining the values of critical process parameters in melt spinning to optimize the qualities of denier, tenacity, breaking elongation, and denier variance in as‐spun polypropylene yarn. An orthogonal array in the Taguchi method defines the minimum set of parameter‐level combinations that are experimentally tested. The significant process parameters, namely the third extruder barrel temperature, spinning temperature, metering pump speed, and take‐up velocity, are identified on the basis of the analysis of variance and F test. After a confirmation experiment is conducted to ensure the reproducibility of the experimental results, the back‐propagation neural network establishes a continuous system linking 10 process parameters and four qualities. The technique for order preference by similarity to an ideal solution can be used to obtain a performance measure for assessing multiple qualities. The genetic algorithm attempts to find parameter values for optimizing the quality performance, including the denier, tenacity, breaking elongation, and denier variance. Finally, the experimental results demonstrate that the smallest denier, largest tenacity, smallest breaking elongation, and second smallest denier variance of as‐spun polypropylene yarn can be achieved with the proposed approach in melt spinning. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 2532–2541, 2006
Microstructural imaging and characterization of the mechanical, chemical, thermal, and swelling properties of starch–chitosan blend films
Authors: Mathew Sindhu , Brahmakumar M. , Abraham T. Emilia 
Published: February 2006

AbstractChitosan has wide range of applications as a biomaterial, but barriers still exist to its broader use due to its physical and chemical limitations. The present study evaluated the properties of the polymeric blend films obtained from chitosan and potato starch by the casting/solvent evaporation method. The swelling properties of the different films studied as a function of pH showed that the sorption ability of the blend films increased with the increasing content of starch. Fourier transform infrared (FTIR) analyses confirmed that interactions were present between the hydroxyl groups of starch and the amino groups of chitosan in the blend films while the x‐ray diffraction (XRD) studies revealed the films to exhibit an amorphous character. Thermogravimetric analyses showed that in the blend films, the thermal stability increased with the increasing starch content and the stability of starch and chitosan powders reduced when they were converted to film. The differential scanning calorimetry (DSC) studies revealed an endotherm corresponding to water evaporation around 100°C in all the films and an exotherm, corresponding to the decomposition in the chitosan and blend films. Scanning electron microscopy (SEM) observations indicated that the blend films were less homogenous and atomic force microscopy (AFM) studies revealed the chitosan films to be smooth and homogenous, while the starch films revealed characteristic granular pattern. The blend films exhibited an intermediate character with a slight microphase separation. The starch–chitosan blend films exhibited a higher flexibility and incorporation of potato starch into chitosan films improved the percentage elongation. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 176–187, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Search for optimal coupling reagent in multiple peptide synthesizer
Authors: Hachmann John , Lebl Michal 
Published: February 2006

AbstractTen different coupling reagents and their combinations were tested in parallel in the synthesis of four model peptide sequences. Significant differences were found between uronium and phosphonium salt‐based reagents and carbodiimide. Diisopropylcarbodiimide was identified as an optimal reagent based on the purity of the product, stability of the reagent, and convenience of handling on plate‐based multiple parallel centrifugation synthesizer. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 340–347, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Investigating the permanent electric dipole moment of β‐lactoglobulin fibrils, using transient electric birefringence
Authors: Rogers S. S. , Venema P. , van der Ploeg J. P. M. , van der Linden E. , Sagis L. M. C. , Donald A. M. 
Published: February 2006

AbstractAmyloid fibrils, which are polymeric assemblies of protein molecules, have been intensively studied on a structural level, yet due to complications such as the disorder within the molecules, several aspects of their structure remain mysterious. Similarly, the kinetics of assembly are not well understood. Here we investigate the electric dipole moment of β‐lactoglobulin fibrils, a model amyloid fibril system, by applying the technique of transient electric birefringence. This moment appears to be large, and comparable to the total moment of the constituent protein monomers if they were joined in a chain, head‐to‐tail, without changing conformation, suggesting an ordered joining of monomers in the fibril. Such an ordered assembly may have implications for the assembly mechanism of β‐lactoglobulin fibrils in particular, and amyloid fibrils in general. © 2006 Wiley Periodicals, Inc. Biopolymers 82: 241–252, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Sorption of Chromium(VI) from Aqueous Solution by Cassava (Manihot sculenta Cranz.) Waste Biomass
Authors: Horsfall Michael , Ogban Fred , Akporhonor Eyitemi Emmanuel 
Published: February 2006

AbstractThe sorption of highly toxic CrVI ions by cassava waste biomass was quantitatively investigated. The sorption was found to be influenced by several physico‐chemical factors such as agitation speed, temperature, contact time, pH, and sorbent/sorbate ratio. The adsorption data at equilibrium were fitted to Freundlich and Langmuir isotherms. The monolayer sorption capacity was found to be 61.79 mg of CrVI per gram of biomass. The kinetics of CrVI adsorption to pure cassava‐tuber‐bark wastes were determined based on a pseudo‐second‐order‐rate model using the batch‐sorption technique at a temperature of 30°. The kinetics data suggest that the adsorption process is exothermic, and that the rate‐limiting step is physisorption. Negative ΔGads values indicate that the adsorption is spontaneous and exothermic in nature. Also, under optimal conditions (in agitated 1M H2SO4 at 30°), the cassava waste biomass appears to be recyclable.
New Antioxidant Phenolic Glycosides from Walsura yunnanensis
Authors: Luo Xiao‐Dong , Wu Da‐Gang , Cai Xiang‐Hai , Kennelly Edward J. 
Published: February 2006

AbstractFour new polyphenolic glycosides (1–4) were isolated from the BuOH extract of the bark of Walsura yunnanenis C. Y. Wu. These compounds comprise two lignans, i.e., the 9‐O‐α‐L‐arabinopyranosides 1 and 2 of (−)‐isolariciresinol and of (+)‐5‐methoxyisolariciresinol, respectively, and the two phenolic glycosides 3,4,5‐trimethoxyphenyl 2‐O‐(α‐L‐fucopyranosyl)‐β‐D‐glucopyranoside (3) and 3,5‐dihydroxyphenyl 6‐O‐(4‐hydroxy‐3,5‐dimethoxybenzoyl)‐β‐D‐glucopyranoside (walsuraside; 4). In addition, three known compounds, 3,4,5‐trimethoxyphenyl β‐D‐glucopyranoside, asperglaucide, and butyl α‐D‐fructofuranoside were identified. Their structures were elucidated spectroscopically and by chemical transformation (hydrolysis). The new compounds 1, 2, and 4 displayed significant antioxidant activities, with IC50 values in the range of ca. 42 to 49 μg/ml.
Preoperative palliation of newborn obstructed total anomalous pulmonary venous connection by endovascular stent placement
Authors: Kyser James P. , Bengur A. Resai , Siwik Ernest S. 
Published: February 2006

AbstractPatients with obstructed total anomalous pulmonary venous connection (TAPVC) usually present critically ill and continue to be extremely challenging with presurgical stabilization. We present an extra corporeal membrane oxygenation (ECMO)‐dependent neonate with obstructed TAPVC that was successfully palliated with transvenous stent placement in the obstructed vertical vein. © 2006 Wiley‐Liss, Inc.
Percutaneous closure of postoperative ventricular septal defects with the amplatzer device
Authors: Walsh Mark A. , Coleman David M. , Oslizlok Paul , Walsh Kevin P. 
Published: February 2006

AbstractThe objective of this study was to look at the procedure, the results, and the follow‐up of patients who underwent percutaneous closure of a residual ventricular septal defect (VSD) following a surgical closure using the Amplatzer VSD device. Four patients had an original diagnosis of tetralogy of Fallot, two patients had a patch leak following a surgical repair of a VSD, and three patients had a VSD not repaired at the time of surgery. All patients fulfilled the currently accepted surgical criterion for reoperation (Qp/Qs > 1.5). The mean Qp/Qs was 1.8 ± 0.3 (1.5–2.3). Four patients underwent VSD closure using an Amplatzer perimembranous VSD device and in five patients an Amplatzer muscular VSD device was implanted. We performed percutaneous closure in nine patients. The size of the residual shunt ranged from 6 to 14 mm and the size of device used ranged from 8 to 16 mm. The arteriovenous loop needed to be recreated in two patients because of failure to advance the delivery sheath. There was complete closure of the defect in six cases, and a small residual shunt remained in three cases. Percutaneous closure of postoperative VSDs appears to be an effective way to resolve a hemodynamically significant residual shunt. There were no difficulties encountered with implantation of the devices. These promising short‐term results need reinforcement with additional long‐term data. © 2006 Wiley‐Liss, Inc.
Stenting coronary trifurcation lesions: Is “ménage à trois” the solution?
Authors: El‐Jack Seifeddin S. , Pornratanarangsi Suwatchai , Ormiston John A. , Webster Mark W.I. 
Published: February 2006

AbstractPercutaneous treatment of coronary stenoses involving important side branches remains a challenge to the interventionist. We describe two cases of stent deployment in coronary trifurcation lesions. Triple kissing balloon inflation appears important for achieving an optimal angiographic and clinical result. © 2006 Wiley‐Liss, Inc.