bluuebunny/crossref_metadata_2025_split huggingface dataset:
Failure of multimaterial fusion bonding interface generated during over‐injection molding/thermoforming hybrid process
Authors: Aurrekoetxea J. , Castillo G. , Cortes F. , Sarrionandia M. A. , Urrutibeascoa I. 
Published: July 2006

AbstractThe effects of processing parameters on the strength of the fusion bonding interface have been investigated. The interface was generated when an isotactic polypropylene homopolymer was injection molded on a solid self‐reinforced polypropylene substrate. The interface strength was measured in shear configuration, and the melting behavior of substrate was studied using differential scanning calorimetry. The results show that strong bonding interface can be achieved when the correct processing parameters are chosen. The interfacial strength is largely improved if the interface temperature is higher than the melting temperature of the substrate layer, and in these specimens failure does not take place at the interface. Furthermore, for a fixed interface temperature, interface strength increases with thermal gradient. Finally, in the analyzed holding pressure range, pressure apparently has no effect on strength. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 261–265, 2006
Study on copolymerization of ethylene/1‐hexene catalyzed by a novel polystyrene‐supported metallocene catalyst
Authors: Wang Wenqin , Wang Li , Dong Xiaochen , Sun Tianxu , Wang Jianfeng 
Published: July 2006

AbstractEthylene/1‐hexene copolymerization was carried out with polystyrene‐supported metallocene catalyst. It was found that the kinetic of the copolymerization was strongly influenced by the steric hindrance of carrier. The influences of 1‐hexene concentration in the feed on catalyst productivity and comonomer reactivity were investigated. The microstructure of resultant copolymer was analyzed by 13C NMR. It was found that the different carriers have slight effect on the composite of copolymer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1574–1577, 2006
Functionalization of chitosan membranes through phosphorylation: Atomic force microscopy, wettability, and cytotoxicity studies
Authors: Amaral I. F. , Granja P. L. , Melo Luís V. , Saramago B. , Barbosa M. A. 
Published: July 2006

AbstractGrafting negatively charged groups such as phosphates is a well‐known strategy for inducing the deposition of apatite‐like layers under simulated physiological conditions. In this investigation, chitosan was phosphorylated in an attempt to enhance its osteoconduction. Chitosan membranes were phosphorylated at 30°C with the H3PO4/Et3PO4/P2O5/butanol reaction system for periods up to 48 h. This method is an alternative to the phosphoric acid/urea/dimethylformamide phosphorylation method, which involves the use of much higher temperatures. In this study, the effects of the phosphorylation reaction time on the surface morphology and surface free energy of phosphorylated membranes were investigated with atomic force microscopy and static‐contact‐angle measurements, respectively. In addition, the modified membranes were evaluated with respect to their cytotoxicity toward bone cells through the incubation of human osteoblastic cells with extracts of the materials for two different periods: 24 and 120 h. The results revealed a reduction of the average surface roughness at the nanometer scale with increasing phosphorylation reaction time. Wettability studies showed an increase in the polar component of the surface free energy with increasing reaction time as a result of the increase in the phosphate surface concentration. Cytotoxicity studies revealed no cytotoxic effect of phosphorylated membranes on osteoblastic cells, regardless of the incubation period. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 276–284, 2006
Fractionation of a silk fibroin hydrolysate and its protective function of hydrogen peroxide toxicity
Authors: Yeo Joo‐Hong , Lee Kwang‐Gill , Kweon Hae‐Yong , Woo Soon‐Ok , Han Sang‐Mi , Kim Sung‐Su , Demura Makoto 
Published: July 2006

AbstractFractionated components of Bombyx mori silk fibroin, which were hydrolyzed with protease, were prepared with a preparative‐recycling high‐performance‐liquid‐chromatography system to evaluate the protective effects of molecular‐weight‐controlled B. mori silk fibroin components on H2O2‐injured neuronal cells. Three major fractions, having molecular weights less than about 1500, were first collected with the recycling techniques. The highest protective effect of the molecular‐weight‐controlled B. mori silk fibroin components on H2O2‐injured neuronal cells was obtained when a fraction with a molecular weight of approximately 1400 was used. This protective effect of the silk fibroin hydrolysate on H2O2‐injured neuronal cells was suggested to correlate with the contents of aromatic amino acids such as tyrosine and phenylalanine.
© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 772–776, 2006
Evaluation of anionic‐ and cationic‐supported hydrogel membranes for sorption of Th(IV) and U(VI) ions from nitric acid medium
Authors: Hegazy E. A. , El‐Gammal B. , Khalil F. H. , Mabrouk T. M. 
Published: July 2006

AbstractFunctionalized membranes were obtained by radiation‐induced graft copolymerization (RIGP) of acrylamide‐acrylic acid (AAm‐AAc) and acrylamide‐4‐vinyl pyridine (AAm‐4VP) binary monomers on both low‐density polyethylene and polypropylene films. The supporting conditions as inhibitor concentration, irradiation dose comonomer compositions and concentrations were studied and optimized. The prepared membranes were characterized using SEM, DTA‐TG, and FTIR. They proved that supporting the selected hydrogels on the base films have modified their structure and enhanced their thermal and mechanical characteristics. The sorption characteristics of Th(IV) and U(VI) on the different membranes were studied. The amount of ions sorbed at equilibrium was found to increase with increase in the degree of graft at certain conditions. The kinetics of sorption was also studied and found to obey the Lagergren and Morris–Weber kinetic models. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 320–332, 2006
Preparation of interpenetrating polymer network gel beads for dye absorption
Authors: Kusuktham Boonsri 
Published: July 2006

AbstractPreparation of interpenetrating polymer network (IPN) gel beads for dye absorption was carried out by using simultaneous crosslinking method. First, sodium alginate (SA), 3‐(methacrylamido) propyl trimethyl ammonium chloride (MAPTAC), and/or acrylamide (AM), K2S2O8, and N,N′‐methylenebisacrylamide (MBAM) were mixed in aqueous solution. The beads were prepared using K2S2O8 and MBAM as the initiator and crosslinking agent, respectively. Then, the solution was dropped into CaCl2 solution mixed with N,N,N′,N′‐tetramethylethylenediamine (TMEDA). The former was used as the crosslinking agent of alginate and the latter was used as the accelerator for the polymerization of monomer in the alginate solution. The gel bead composed of only alginate was also prepared to compare the properties with IPN gel bead. The components in IPN gel bead were examined by FTIR analysis. The factors effecting the particle size of alginate and IPN gel beads were investigated. In alginate gel bead, the concentration of solution affected the particle size, whereas type of monomer affected the particle size of IPN gel bead. The IPN gel bead had smooth surface (from SEM results), different from the alginate bead. Alginate content caused the swelling behavior of dried IPN beads. Cationic dye was absorbed by crosslinked alginate gel bead. The absorption of reactive dye by IPN gel bead was a result of its cationic charge. The absorption density of IPN gel beads was the reciprocal of the absorbent dosage. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1585–1591, 2006
The tensile properties of strain‐crystallizing vulcanizates. III. The superiority of conventional over peroxide vulcanizates in terms of network microstructure
Authors: Horst M. Van Der , McGill W. J. , Woolard C. D. 
Published: July 2006

AbstractIt is proposed that, when vulcanization is performed using peroxides, crosslinking leads to a simple network, whereas in conventional vulcanization crosslinking a partially interpenetrating polymer network (PIPN) is formed. Two unfilled polyisoprene networks of similar crosslink density, produced with dicumyl peroxide and 2‐bisbenzothiazole‐2,2′‐disulfide/sulfur formulations, were compared with respect to the effect of strain rate on their stress–strain and hysteresis curves at room and elevated temperatures. At high elongations, the stress–strain curves for peroxide vulcanizates show a steeper upturn than for conventional vulcanizates, but have lower tensile strength and elongation at break. On increasing the extension rate, stress–strain curves for peroxide vulcanizates rise less steeply, while conventional vulcanizates rise more steeply. For both vulcanizates the hysteresis ratio decreases on increasing the rate at which samples are extended and retracted. The effect on conventional vulcanizates is less than on peroxide vulcanizates. It is suggested that chains in peroxide networks disengage increasingly rapidly at higher strains, allowing increased strain‐induced crystallization. Rapid strain‐induced crystallization leads to low ultimate tensile strength (UTS). In more complex PIPNs, the disengagement and alignment of chains are retarded. The increased nonuniform extension of chains promotes early strain‐induced crystallization at low extensions, but overall it reduces the rate of crystallization, which occurs over a wider range of strains. This improves UTS and elongation. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 876–884, 2006
Application of electrochemically produced and oxidized poly(3,4‐ethylenedioxythiophene) as anticorrosive additive for paints: Influence of the doping level
Authors: Liesa Francisco , Ocampo Cintia , Alemán Carlos , Armelin Elaine , Oliver Ramón , Estrany Francesc 
Published: July 2006

AbstractThis work investigates the resistance against marine corrosion of an epoxy‐based coating modified by the addition of electrochemically produced and oxidized poly(3,4‐ethylenedioxythiophene) (PEDOT). For this purpose, electrodeposition of PEDOT was performed on steel electrodes by electrochemical polymerization of 3,4‐ethylenedioxythiophene. The doping level of the resulting material was increased by chronoamperometry and chronopotentiometry (CP), three different oxidation degrees being achieved. The electrochemical and electrical properties of such three samples, which were used as anticorrosive additives, were examined. Furthermore, the physical properties of the coating before and after addition of the conducting polymers were characterized using FTIR, thermal analyses, and mechanical properties evaluations. Accelerated corrosion tests indicated that the polymer with the highest amount of positive charge per monomeric unit, which was achieved by CP, enhances considerably the anticorrosive protection imparted by the coating. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1592–1599, 2006
Preparation and properties of microporous cellulose membranes from novel cellulose/aqueous sodium hydroxide solutions
Authors: Cao Yu , Tan Huimin 
Published: July 2006

AbstractMicroporous cellulose membranes were prepared from novel cellulose/aqueous sodium hydroxide solutions by coagulation with aqueous H2SO4 solutions. The free and glass‐contacting surface morphology of the microporous cellulose membranes showed an asymmetric porous structure. The morphological structure, tensile properties, and permeability of the microporous cellulose membranes could be controlled by changes in the coagulation conditions such as the coagulant concentration and the coagulation time.
© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 920–926, 2006
Structure and properties of nanocomposites based on poly(butylene succinate) and organically modified montmorillonite
Authors: Ray Suprakas Sinha , Okamoto Kazuaki , Okamoto Masami 
Published: July 2006

AbstractPoly(butylene succinate) and organically modified montmorillonite nanocomposites with there different compositions were prepared via melt blending in a twin‐screw extruder. The structure of the nanocomposites was studied with X‐ray diffraction and transmission electron microscopy, which revealed the formation of intercalated nanocomposites, regardless of the silicate loading. Dynamic mechanical analysis revealed a substantial increase in the storage modulus of the nanocomposites over the entire temperature range investigated. The tensile property measurements showed a relative increase in the stiffness with a simultaneous decrease in the yield strength in comparison with that of neat poly(butylene succinate). The oxygen gas barrier property of neat poly(butylene succinate) improved after nanocomposite preparation with organically modified montmorillonite. The effect of the layered‐silicate loading on the melt‐state linear viscoelastic behavior of the intercalated nanocomposites was also investigated.
© 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 777–785, 2006
Synthesis and characterization of modified bismaleimide/polysulfone semi‐interpenetrating polymer networks
Authors: Kurdi Jamal , Kumar Ashwani 
Published: July 2006

AbstractThe present work reports a new method of preparing semi‐interpenetrating polymer network (semi‐IPN) membranes through in situ polymerization of bismaleimide (BMI) within polysulfone (PSF). It was found that BMI could be polymerized at ambient conditions in the presence of a proton donor and PSF without the use of an initiator or a catalyst. Chemical structure characterization of these semi‐IPNs by Fourier transform infrared attenuated total reflection (FTIR‐ATR) revealed the possibility of imide cleavage and formation of amic acid when BMI polymerization was continued for a longer time while X‐ray photoelectron spectroscopy (XPS) revealed the protonation of imide nitrogen at shorter polymerization time. It was also found that size of thermoset BMI phase within the PSF thermoplastic has a significant impact on glass‐transition temperature of resulting semi‐IPN. By controlling the thermoset/thermoplastic phase separation of semi‐IPNs through dope composition and formation techniques, gas separation membranes with comparable selectivity and permeance that were up to 12 times higher than corresponding PSF membranes were formed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 369–379, 2006
Preparation and characterization of high refractive index thin films of TiO2/epoxy resin nanocomposites
Authors: Guan Cheng , Lü Chang‐Li , Liu Yi‐Fei , Yang Bai 
Published: July 2006

AbstractBy using sol–gel method, amorphous titania was introduced into epoxy matrix to prepare a series of high refractive index TiO2/epoxy resin nanocomposite films. To increase the refractive index of the hybrid films, triethoxysilane‐capped trimercaptothioethylamine (TCTMTEA), a new kind of high refractive index coupling agent was synthesized from trimercaptothioethylamine (TMTEA). In the experiment, TCTMTEA acted as the solidification agent together with TMTEA except being used as the coupling agent. The hybrid films have been characterized via FTIR, AFM, DSC, TGA, etc. The experimental results showed that the amorphous TiO2 had been dispersed uniformly in the organic polymer matrix with the size smaller than 100 nm in each sample. More importantly, the refractive index of this kind of materials can be continuously adjusted from 1.61 to 1.797 with the content of TiO2 increasing from 0% to 65% in mass, and the continuously adjusted refractive index is very important for the applications in optical antirefractive films. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1631–1636, 2006
Investigation on gradient dielectric characteristics of bamboo (Dentroclamus strictus)
Authors: Chand Navin , Jain Deepak , Nigrawal Archna 
Published: July 2006

AbstractDependence of dielectric constant (ε′) and dielectric dissipation factor (tan δ) on distance from outermost skin to the center of bamboo has been determined. Dielectric measurements have been done in the temperature range of 24–120°C and in the frequency range, 4–100 kHz. Gradient behavior in ε′ and tan δ has been found in bamboo. It has also been observed that ε′ and tan δ increase with increasing temperature and decrease with increasing frequency. Relaxation times have been calculated for the four samples at 80, 90, and 100°C temperatures, which show that relaxation time decreases with the increase of temperature because of the increased molecular mobility. A continuous increase in the hardness from center (48) to outer surface (70) and density from 0.45 to 0.80 g/cc has been observed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 380–386, 2006
Swelling characteristics and in vitro drug release study with pH‐ and thermally sensitive hydrogels based on modified chitosan
Authors: El‐Sherbiny I. M. , Abdel‐Bary E. M. , Harding D. R. K. 
Published: July 2006

AbstractThe grafting of a poly(ethylene glycol) diacrylate macromer onto a chitosan backbone was carried out with different macromer concentrations. The grafting was achieved by (NH4)2Ce(NO3)6‐induced free‐radical poly merization. Biodegradable, pH‐ and thermally responsive hydrogels of poly(ethylene glycol)‐g‐chitosan crosslinked with a lower amount of glutaraldehyde were prepared for controlled drug release studies. Both the graft copolymers and the hydrogels were characterized with Fourier transform infrared, elemental analysis, and scanning electron microscopy. The obtained hydrogels were subjected to equilibrium swelling studies at different temperatures (25, 37, and 45°C) in buffer solutions of pHs 2.1 and 7.4 (similar to those of gastric and intestinal fluids, respectively). 5‐Fluorouracil was entrapped in these hydrogels, and equilibrium swelling studies were carried out for the drug‐entrapped gels at pHs 2.1 and 7.4 and 37°C. The in vitro release profile of the drug was established at 37°C and pHs 2.1 and 7.4. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 977–985, 2006
Wetting behavior of thermally bonded polyester nonwoven fabrics: The importance of porosity
Authors: Zhu Lu , Perwuelz Anne , Lewandowski Maryline , Campagne Christine 
Published: July 2006

AbstractThe wetting properties of thermally bonded polyester nonwoven fabrics with different basis weights were studied. These nonwovens had the same composition: 85% poly(ethylene terephthalate) and 15% poly(butylene terephthalate) fibers. Two techniques, the 3S wicking test and sessile drop method, yielded similar water contact angles for all the nonwovens, but these results differed from the values obtained with the single fibers. In the nonwoven fabrics, the pore structure played a dominant role in the wetting properties: the existence of large pores in the thinner nonwovens reduced the dimensions of the liquid–solid interfacial perimeter. Compared with the water contact angle of the constituent single fibers, the contact angle of the fabrics was increased. A crenellated surface model was created to quantify the influence of pores on the wettability of nonwovens. It was possible to deduce the surface porosity of the fabric with this model, but only in the case of contact with nonwetting liquids such as water: this surface porosity corresponded only to the outermost layers of the fabric structure. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 387–394, 2006
Swelling and release kinetics of larvicide‐containing chitosan/cashew gum beads
Authors: Paula Haroldo C. B. , de Paula Regina C. M. , Bezerra Sterlane K. F. 
Published: July 2006

AbstractA new pesticide formulation (bead) based on chitosan (CH) and cashew gum (CG) containing dichlorvos [2,2‐dichlorovinyldimethyl phosphate (DDVP)] was prepared and investigated as a larvicide for Aedes aegypti control. Beads were characterized with respect to their size, shape, larvicide loading, swelling, and in vitro and in vivo release kinetics. CH and CH/CG beads were loaded with DDVP from 5.15 to 71.4%. In the first hour, the in vitro release was similar for CH and CH/CG beads, faster release being observed after 5 h for CH/CG beads; at equilibrium (30 h), CH beads released up to 55% of the larvicide, and CH/CG beads reached 66%. The data were fitted to a mathematical model, being in good agreement with the literature. In vivo release showed that CH/CG beads reached a plateau after 30 h, resulting in a highest mortality of approximately 60%, whereas CH beads killed only 42% of the larvae by 30 h and seemed not to have released their whole larvicide content even after 72 h. The DDVP lethal dose for 50% mortality was found to be 0.01 ± 0.002 ppm; the persistence studies revealed that after 168 h, 42.5% larval mortality was obtained by CH beads, and only approximately half of that was obtained by CH/CG beads. DDVP‐loaded beads were effective up to 336 h. It could be concluded that beads containing DDVP at an average concentration of 7.2 ppm could provide good larval control up to 7 days. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 395–400, 2006
Flocculation studies based on water‐soluble polymers of grafted carboxymethyl cellulose and polyacrylamide
Authors: Biswal D. R. , Singh R. P. 
Published: July 2006

AbstractGraft copolymers of carboxymethylcellulose and polyacrylamide were synthesized by a ceric‐ion‐induced solution polymerization technique. By the variation of the monomer and catalyst concentrations, six grades of graft copolymers were synthesized. The synthesized graft copolymers were characterized with intrinsic viscosity measurements, IR spectroscopy, and X‐ray diffractometry. The flocculation characteristics of the graft copolymers were studied in kaolin (5 wt %), iron‐ore (10 wt %), and silica (10 wt %) suspensions. The flocculation characteristics of the best performing graft copolymer were then compared with those of various commercially available flocculants. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1000–1007, 2006
Using polymer compounds in place of metal material to make cost‐effective parts
Authors: Huang C. K. , Lee C. S. , Yang C. T. 
Published: July 2006

AbstractThe use of plastic materials in place of metals is attractive because of their versatility and ease of batch fabrication, which reduces costs. This article investigates the possibility of using nylon compounds in place of metal materials to make cost‐effective parts through microinjection molding. Experimental results showed that the plastic parts were well formed with high accuracy and reproducibility through microinjection molding. The average tolerance in the dimensions of the plastic parts was less than 20 μm. The resulting composites with 15 wt % carbon particles exhibited the optimum improvement in accuracy, reproducibility, and wear resistance. In addition, the wear loss of the metal parts without lubrication was 4–10 times higher than that of the polymer compounds. The results revealed that the ball‐screw plates made with nylon compounds exhibited high accuracy, reproducibility, and wear resistance, could be produced at low cost, and they could successfully replace S316 metal parts in microinjection molding. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1645–1652, 2006