bluuebunny/crossref_metadata_2025 huggingface dataset:
Study on the properties of ethylene‐vinyl acetate rubber vulcanizate filled with superfluous magnesium hydroxide/methacrylic acid
Authors: Yu Haiyang , Zhang Yong , Chen Shuguo , Ren Wentan , Hoch Martin , Guo Sharon
Published: August 2010

Ethylene‐vinyl acetate rubber (EVM) vulcanizates cured by dicumyl peroxide (DCP) with excellent mechanical properties were obtained by adding superfluous magnesium hydroxides (MH)/methacrylic acid (MAA). Different factors such as the DCP content and MH content were investigated to reveal their effects on the properties of the MH/MAA‐filled EVM vulcanizates. The formulation of DCP of 2 phr, MH of 60 phr, and MAA of 5 phr is recommended for the EVM vulcanizates with excellent mechanical properties. The stress relaxation and stress softening behavior of MH/MAA‐filled EVM vulcanizates were studied. The stress relaxation and stress softening became faster and more obvious with increasing MH content. The hot air aging resistance of EVM vulcanizates filled with different fillers such as silica and high abrasion furnace were compared, and the MH/MAA‐filled EVM vulcanizates had the best aging resistance at 40‐phr filler content. The MH/MAA‐filled EVM vulcanizates had excellent flame retardancy due to the high MH content. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Dispersion and mechanical properties of a nanocomposite with an organoclay in an ionomer‐compatibilized LDPE matrix
Authors: Santamaría P. , Eguiazabal J. I. , Nazabal J.
Published: August 2010

Widely dispersed low density polyethylene (LDPE) based nanocomposites (Nc's) were obtained in the melt state thanks to their compatibilization with a zinc ionomer of poly(ethylene‐co‐methacrylic acid) (Pema‐Zn). The variables probed were the ionomer and organoclay content ranging from 0 to 20%, and from 0 to 10%, respectively. The TEM images showed that the organoclay is widely exfoliated. Furthermore, we report for the first time that the organoclay is concentrated in irregular zones. Taking into account the compatibility between MMT and the ionomer, it is plausible that the ionomer clusters are also concentrated in the organoclay‐rich regions. This heterogeneous microstructure has a positive effect on the mechanical properties since the Nc's are ductile, and the modulus increases were among the largest reported for LDPE, attaining a 160% increase with a 10% montmorillonite (MMT) content. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Sorption of binary mixtures of toluene + lower aliphatic alcohols C1 – C6 in low‐density polyethylene
Authors: Randová A. , Bartovská L. , Hovorka Š. , Izák P. , Friess K. , Janků J.
Published: August 2010

Sorption gravimetric and volumetric techniques performed at 25°C and at atmospheric pressure were employed to study the preferential and total sorptions from binary liquid mixtures of toluene + lower aliphatic alcohols (C1 – C6) in a high‐pressure low‐density polyethylene membrane and the volume of the swollen membrane. Toluene was preferentially sorbed in all six systems. The total sorbed amount increased from pure alcohol to pure toluene. The experimental volume of the swollen membrane was compared with that calculated under the assumption that interactions between the polymer and liquid mixture were negligible. The composition of the binary liquid mixture sorbed in the polymer as a function of the composition of the bulk solution surrounding the membrane is presented. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The unidirectional glass fiber reinforced furfuryl alcohol for pultrusion. II. Correlation of processing parameters for optimizing the process
Authors: Chen Chin‐Hsing , Chen I‐Ken
Published: August 2010

Unidirectional glass fiber reinforced furfuryl alcohol (FA) composites have been prepared by the pultrusion processes. The optimum processing parameters of the glass fiber reinforced FA composites by pultrusion has been studied. The effects of the optimum processing parameters on the properties (flexural strength, flexural modulus, notched Izod impact strength, glass transition temperature (Tg), dynamic shear storage modulus (E'), shrinkage ratio, and roughness) investigated including die temperature, pulling rate, postcure temperature and time, and filler type and content. Results show that the pultruded composites possessed various optimum pulling rates at different die temperatures. On the basis of the DSC diagram, the swelling ratio and the mechanical properties of pultruded composites, the optimum die temperature can be determined. The mechanical properties and Tg increase at a suitable postcure temperature and time. Furthermore, the properties which decrease due to the degradation of pultruded composites for a long postcure time will be discussed. The mechanical properties of pultruded composites reach a maximum value at various filler content corresponding to the talc and calcium carbonate, respectively, and then decreased. When the fillers are added to the pultruded glass fiber reinforced FA composites, the shrinkage ratio of composites become smaller, and the surface of composites became smooth. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
UV‐curable nanocomposites containing zirconium vinylphosphonate or zirconia
Authors: Macarie Lavinia , Plesu Nicoleta , Iliescu Smaranda , Popa Adriana , Ilia Gheorghe
Published: August 2010

UV‐cured nanocomposite films were prepared from acrylic monomer and two types of nanomaterial: zirconium vinylphosphonate and zirconia, in the presence of a photoinitiator. The films were characterized by FTIR, SEM, and AFM. FTIR spectra showed the disappearance of band assigned to the CC group both of monomer and zirconium vinylphosphonate by polymerization and the presence of the phosphonate group in polymer. The influence of zirconium vinylphosphonate and zirconia content on thermooxidative degradation of polymeric films was studied by thermogravimetry. SEM and AFM images showed that nanomaterials are dispersed in polymer matrix with no macroscopic phase separation. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Optimization of the process variables for the synthesis of starch‐based biodegradable resin using response surface methodology
Authors: Hong Fu‐Liang , Peng Jinchyau , Lui Wai‐Bun
Published: August 2010

Response surface methodology (RSM) was used to analyze the effect of different additives glycerol level (X1) and plasticizer level (X2) on the objective (water solubility index, water absorption index, and Max. loading) attributes of a cornstarch/PHBV blended composite. A rotatable central‐composite design (CCD) was used to develop models for the objective responses. The experiments were run at barrels temperatures 160, 160, 165, and 165°C, respectively, with screw speed 40 rpm and complete feeding (filling ratio = 1). Responses were most affected by changes in plasticizer level (X2) and to a lesser extent by glycerol level (X1). Individual contour plots of the different responses were overlaid, and regions meeting the predicted optimum water solubility index of 4.34%, water absorption index of 4.55 g gel/g dry wt, and Max. loading of 370.06 N were identified at the plasticizer level of 21.06 g, and the glycerol level of 96.11 mL, respectively. These predicted values for optimum process conditions were in good agreement with experimental data. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Narrow size‐distribution poly(methyl methacrylate) nanoparticles made by semicontinuous heterophase polymerization
Authors: Aguilar J. , Rabelero M. , Nuño‐Donlucas S. M. , Mendizábal E. , Martínez‐Richa A. , López R. G. , Arellano M. , Puig J. E.
Published: August 2010

The effect of surfactant (sodium dodecyl sulfate) concentration on particle size, molar masses, glass transition, and tacticity of poly(methyl methacrylate) (PMMA) nanoparticles synthesized by semicontinuous heterophase polymerization under monomer‐starved condition at constant monomer feeding rate is reported. Starved conditions are confirmed by the low amount of residual monomer throughout the reaction and by the fact that the instantaneous polymerization rate is similar to the feeding rate of monomer. Under these conditions, polymer particles in the nanometer range (20–30 nm) were obtained with narrow size distribution (1.07 < Dw/Dn < 1.18), depending of surfactant concentration. Final particle size diminishes as the surfactant concentration is increased. Glass transition temperatures and syndiotactic content (54%–59%) of the produced polymers are substantially higher than those reported for commercial and bulk‐made PMMA. Molar masses are much lower than those expected from termination by chain transfer to monomer, which is the typical termination mechanism in 0–1 emulsion and microemulsion polymerization of this monomer. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of evolved interactions in poly(butylene succinate)/fumed silica biodegradable in situ prepared nanocomposites on molecular weight, material properties, and biodegradability
Authors: Vassiliou Alexandros A. , Bikiaris Dimitrios , El Mabrouk Khalil , Kontopoulou Marianna
Published: August 2010

Poly(butylene succinate) (PBSu)/fumed silica nanocomposites were prepared in situ by condensation polymerization. TEM micrographs verified that the dispersion of the nanoparticles was homogeneous in the PBSu matrix, while some small agglomerates were also formed at a higher SiO2 content. 13C NMR spectra affirmed that the hydroxyl end groups of PBSu could form covalent bonds with the surface silanol groups of SiO2. These interactions affected the molecular weight of the prepared nanocomposites. At low concentrations the SiO2 nanoparticles acted as chain extenders, increasing the molecular weight of PBSu, while at higher loadings they resulted in extended branching and crosslinking reactions, leading to gradually decreased molecular weights. Silica nanoparticles acted as nucleating agents, increasing the crystallization rate of PBSu. However, the degree of crystallinity was slightly reduced. Tensile strength and Young's modulus were significantly increased with increasing SiO2 content. The presence of the nanoparticles resulted in reduced enzymatic hydrolysis rates compared to pure PBSu, attributed to the smaller available organic surface, due to the incorporation of SiO2, and to the existence of branched and crosslinked macromolecules. Dynamic mechanical and rheological properties were also extensively studied. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
In situ formation of nanocomposites based on polyethylene and silica nanospheres
Authors: Zapata Paula , Quijada Raúl , Benavente Rosario
Published: August 2010

Polyethylene nanocomposites containing silica nanospheres, synthesized by the sol–gel method, were produced via in situ polymerization. The silica nanospheres were added together with the catalytic system [metallocene catalyst and methylaluminoxane (MAO) as cocatalyst] directly to the reactor and used for the polymerization of ethylene. The polymerization activity increased slightly in the presence of 1 wt % silica nanospheres in comparison to the homogeneous polymerization sans filler. The Young's modulus of the nanocomposites increased 19–25% without a significant decrease in the elongation at break with respect to the neat polyethylene. The polymer particle morphology was also significantly improved with the incorporation of silica nanospheres. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Melt shear viscosity of PP/Al(OH)3/Mg(OH)2 flame retardant composites at high extrusion rates
Authors: Liang J. Z. , Yang J. , Tang C. Y.
Published: August 2010

The melt apparent shear viscosity (ηa) of polypropylene (PP) composites filled with aluminum hydroxide [Al(OH)3] and magnesium hydroxide [Mg(OH)2] was measured by means of a capillary rheometer under experimental conditions of temperature ranging from 180 to 200°C and apparent shear rate varying from 10 to 2 × 103 s−1, to identify the effects of the filler particle content and size on the melt viscosity. The results showed that the melt shear flow of the composites obeyed the power law and presented pseudoplastic behavior. The dependence of ηa on temperature was consistent with the Arrhenius equation. The sensitivity of ηa for the composite melts to temperature was greater than that of the unfilled PP, and weakened with increasing apparent shear rate. The ηa increased linearly with an increase of the weigh fraction of the flame retardant, especially in the low apparent shear rate region. The ηa of the composites decreased slightly with an increase of particle size of flame retardant. Moreover, the variation for the ηa with particle size of flame retardant was much less than with apparent shear rate under these test conditions. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Sensing behaviors of polymer/carbon nanotubes composites prepared in reversed microemulsion polymerization
Authors: Li Zhenhua , Li Qiang , Shang Songmin , Li Liang , Yang Xiaoming , Yu Xianghua , Yan Guoping
Published: August 2010

Polystyrene/carbon nanotubes composites were readily prepared by reversed microemulsion polymerization. Compared with the composites prepared by solution mixing, the uniform dispersion of carbon nanotubes in polymer matrix could be obtained more easily and the thermal and electrical properties of the as‐prepared composites were also enhanced. The as‐prepared composites were deposited onto a microelectrode array to fabricate a vapor sensor. The response for different organic vapors was evaluated by monitoring the change in the resistance of the composites upon exposure to various gases. The change in resistance was of the order of about 103 for the composites prepared by reversed microemulsion polymerization. The chemical sensors based on the composites prepared by reversed microemulsion polymerization presented excellent reproducibility and reversibility in response. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Entrapment of urease in poly(1‐vinyl imidazole)/poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) network
Authors: Şenel Mehmet , Çevik Emre , Abasıyanık M. Fatih , Bozkurt Ayhan
Published: August 2010

In this article, urease was immobilized in a conducting network via complexation of poly(1‐vinyl imidazole) (PVI) with poly(2‐acrylamido‐2‐methyl‐1‐propanesulfonic acid) (PAMPS). The preparation method for the polymer network was adjusted by using Fourier transform infrared (FTIR) spectroscopy. A scanning electron microscope (SEM) study revealed that enzyme immobilization had a strong effect on film morphology. The proton conductivity of the PVI/PAMPS network was measured via impedance spectroscopy, under humidified conditions. The basic characteristics (Michealis‐Menten constants, pHopt, pHstability, Topt, Tstability, reusability, and storage stability) of the immobilized urease were determined. The obtained results showed that the PAA/PVI polymer network was suitable for enzyme immobilization. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Organic acids catalyzed polymerization of ε‐caprolactone: Synthesis and characterization
Authors: Oledzka Ewa , Narine Suresh S.
Published: August 2010

Environmentally friendly organocatalytic synthesis of aliphatic polyesters was studied. The catalysis investigated is novel, and lends itself well to the potential production of valuable biodegradable products. The reactions were based on an organic acids‐catalyzed ring‐opening polymerization of ε‐caprolactone with fatty acid derivatives as the initiator and were performed in the absence of solvents. The chemical structures of the functionalized polymers were confirmed by1H and13C‐NMR spectra. Polymers with different molecular weights, in the range 10,900–15,200 were obtained in the presence of fumaric acid as catalyst. The thermal properties of the functionalized PCLs were determined by modulated differential scanning calorimetry and thermogravimetric analysis. The MDSC results verified that the crystallinity and the melting point of the lipid‐functionalized polymers were lower than that of the unfunctionalized poly(ε‐caprolactone). The hydrolytic degradation of the functionalized polymer was also investigated. The result shows the degradation rate was affected by the presence of oleic acid derivatives in the polymer molecule. The lipid‐functionalized polymers synthesized by the metal‐free polymerization systems seem to be suitable biodegradable polyesters for use in biomedical and pharmacological applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and characterization of novel lipid functionalized poly(ε‐caprolactone)s
Authors: Oledzka E. , Kong X. , Narine S. S.
Published: August 2010

A series of novel lipid functionalized poly(ε‐caprolactone)s (PCLs) were synthesized through ROP of ε‐caprolactone in the presence of threo‐9,10‐dihydroxyoctadecanoic acid, synthesized from oleic acid. PCLs with different molecular weights were obtained by controlling the molar ratio of the initiator to the monomer. DSC and XRD analysis indicate that the crystallinity of PCLs decreased when compared to unfunctionalized PCL. The enzymatic degradation study shows that for samples with lower lipid derivatives content, a higher enzymatic degradation rate was observed because the lipase enzymes attack the ester bonds of the polymer; increased lipid content therefore inhibits the action of the lipase enzymes. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis of poly(D,L‐lactic acid) modified by triethanolamine by direct melt copolycondensation and its characterization
Authors: Luo Yu‐Fen , Wang Zhao‐Yang , Ye Rui‐Rong , Luo Shi‐He , Yang Li‐Ting
Published: August 2010

Using D,L‐lactic acid (LA) and multifunctional group compound triethanolamine (TEA) as starting materials, a novel biodegradable material poly(D,L‐lactic acid‐triethanolamine) [P(LA‐TEA)] was directly synthesized by simpler and practical melt polycondensation. The appropriate synthetic condition was discussed in detail. When the molar feed ratio LA/TEA was 30/1, the optimal synthesis conditions were as follows: a prepolymerization time of 12 h; 0.5 weight percent (wt %) SnO catalyst; and melt copolycondensation for 8 h at 160°C, which gave a novel star‐shaped poly(D,L‐lactic acid) (PDLLA) modified by TEA with the maximum intrinsic viscosity [η] 0.93 dL g−1. The copolymer P(LA‐TEA) as a different molar feed ratio was characterized by [η], Fourier transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H‐NMR), gel permeation chromatography (GPC), differential scanning calorimetry (DSC), and X‐ray diffraction (XRD). Increasing the molar feed ratio of LA/TEA, Tg and Mw increased. However, all copolymers were amorphous, and their Tg (12.2°C–32.5°C) were lower than that of homopolymer PDLLA. The biggest Mw was 9400 Da, which made the biodegradable polymer be potentially used as drug delivery carrier, tissue engineering material, and green finishing agent in textile industry. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Nanoclay filled soy‐based polyurethane foam
Authors: Liang Kaiwen , Shi Sheldon Q.
Published: August 2010

Polyurethane foam was fabricated from polymeric diphenylmethane diisocyanate (pMDI) and soy‐based polyol. Nanoclay Cloisite 30B was incorporated into the foam systems to improve their thermal stabilities and mechanical properties. Neat polyurethane was used as a control. Soy‐based polyurethane foams with 0.5–3 parts per hundred of polyols by weight (php) of nanoclay were prepared. The distribution of nanoclay in the composites was analyzed by X‐ray diffraction (XRD), and the morphology of the composites was analyzed through scanning electron microscopy (SEM). The thermal properties were evaluated through dynamic mechanical thermal analysis (DMTA). Compression and three‐point bending tests were conducted on the composites. The densities of nanoclay soy‐based polyurethane foams were higher than that of the neat soy‐based polyurethane foam. At a loading of 0.5 php nanoclay, the compressive, flexural strength, and modulus of the soy‐based polyurethane foam were increased by 98%, 26%, 22%, and 65%, respectively, as compared to those of the neat soy‐based polyurethane foam. The storage modulus of the soy‐based polyurethane foam was improved by the incorporation of nanoclay. The glass transition temperature of the foam was increased as the nanoclay loading was increased. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Studies on the physico‐mechanical, thermal, and morphological behaviors of high density polyethylene/coleus spent green composites
Authors: Syed Murtuza Ali , Akhtar Sania , Siddaramaiah  , Syed Akheel Ahmed
Published: August 2010

This study is aimed at utilizing nutraceutical industrial waste and reducing carbon footprints of plastics. Eco‐friendly “green composites” of high density polyethylene (HDPE) were fabricated using coleus spent (CS)—a nutraceutical industrial waste as reinforcing filler and maleic anhydride‐graft‐polyethylene (MA‐g‐PE) as compatibilizer. Composites were fabricated with 5, 10, 15, and 20% (w/w) of CS by extrusion method. The fabricated HDPE/CS composites were evaluated for mechanical and thermal behavior. A slight improvement of about 5% in tensile strength and marked improvement of about 25% in tensile modulus for 20 wt % CS filled HDPE composites was noticed. The effect of CS content on rheological behavior was also studied. Thermal characteristics were performed using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). TGA thermogram indicated increased thermal stability of CS‐filled composites. From TGA curves the thermal degradation kinetic parameters of the composites have been calculated using Broido's method. The enthalpy of melting (ΔHm) obtained from DSC curves was reduced with increase in CS content in HDPE matrix, due to decrease in HDPE content in composite systems. An increase in CS loading increased the water absorption behavior of the composites slightly. Morphological behavior of cryo‐fractured composites has been studied using scanning electron microscopy. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Factorial optimization of the effects of extrusion temperature profile and polymer grade on as‐spun aliphatic–aromatic copolyester fibers. II. Crystallographic order
Authors: Younes Basel , Fotheringham Alex
Published: August 2010

By using factorial experimental design, a range of crystallographic orders for as‐spun linear aliphatic–aromatic copolyester fibers have been characterized with the aid of wide angle X‐ray diffraction measurements. Full‐Width Half‐Maximum of an X‐ray scattering profile (FWHM) has been quantitatively assessed as responses to polymer grades denoted by melt flow index (MFI) and to extrusion temperature zones in the extrusion equipment used to produce the as‐spun fibers. With the advantages of the factorial experimental design in the development of fiber process technology, the enhanced statistical approach specifies the direction of change of the polymer's melt flow index and extrusion temperature profile for increasing or reducing crystallographic order. The produced as‐spun aliphatic aromatic copolyester fiber is an environmentally‐friendly attractive, alternative to conventional chemical fibers for different applications. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of multiwalled carbon nanotubes on crystallization behavior of poly(vinylidene fluoride) in different solvents
Authors: He Linghao , Sun Jing , Zheng Xiaoli , Xu Qun , Song Rui
Published: August 2010

In this study, the poly(vinylidene fluoride) (PVDF)—multiwalled carbon nanotubes (MWNTs) composites have been prepared by solution casting in two different solvents: dimethyl sulfoxide (DMSO) and dimethylacetamide (DMAc). Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimeter (DSC) results showed that the crystal phases of PVDF are quite different in the two solvents. When DMSO is used as the solvent, the PVDF crystalline phases could be greatly alternated from α‐form to β‐form by the incorporation of MWNTs. While the crystalline structure of PVDF hardly change in the case of DMAc. The DSC and polarized optical microphotographs implied that MWNTs not only act as nucleating agents for PVDF but also confine the crystallization of PVDF. Besides, it was found that the storage modulus (E′) of the composites were significantly enhanced with an appropriate content of MWNTs. And when using DMSO as the solvent, one relaxation process emerges in the loss tan δ (loss factor) curves of the neat PVDF and PVDF/MWNTs composites, while it was not observed in the DMAc system. The obtained results revealed that varing solvents have different effects on the crystallization behavior of PVDF with the addition of MWNTs. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Pineapple leaf fiber reinforced thermoplastic composites: Effects of fiber length and fiber content on their characteristics
Authors: Chollakup Rungsima , Tantatherdtam Rattana , Ujjin Suchada , Sriroth Klanarong
Published: August 2010

Pineapple leaf fiber (PALF) was used as a reinforcement in polyolefins. Polypropylene (PP) and low‐density polyethylene (LDPE) composites with different fiber lengths (long and short fibers) and fiber contents (0–25%) were prepared and characterized. The results showed that the tensile strength of the composites increased when the PALF contents were increased. It was observed that the composites containing long fiber PALF were stronger than the short fiber composites as determined by greater tensile strength. An SEM study on the tensile fractured surface confirmed the homogeneous dispersion of the long fibers in the polymer matrixes better than dispersion of the short fibers. The unidirectional arrangement of the long fibers provided good interfacial bonding between the PALF and polymer which was a crucial factor in achieving high strength composites. Reduction in crystallinity of the composites, as evident from XRD and DSC studies suggested that the reinforcing effect of PALF played an important role in enhancing their mechanical strength. From the rule of mixtures, the stress efficiency factors of the composite strength could be calculated. The stress efficiency factors of LDPE were greater than those of PP. This would possibly explain why the high modulus fiber (PALF) had better load transfers to the ductile matrix of LDPE than the brittle matrix of PP. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Compatibilizing effect of functionalized polyphosphazene on the properties of poly(phenylene oxide)/vectra a blend system
Authors: Bose S. , Das C. K. , Saxena A. K. , Ranjan A.
Published: August 2010

The effect of functionalized polyphosphazene on the thermal, rheological, and morphological properties of PPO (poly(phenylene oxide))/liquid crystalline polymer (Vectra A) blend has been investigated by means of the capillary rheometry, mechanical testing, and scanning electron microscopy (SEM) in this study. The rheological measurements show that compatibilized blends exhibit substantial rise in viscosity in comparison to uncompatilized blend especially pronounced at lower shear rates which results in improved interfacial adhesion. DMA study highlights that polyphosphazene could be used as an effective compatibilizer for the concerned blend system. SEM study reveals fine fibrillation of liquid crystalline polymers in presence of compatibilizer and the fibers are oriented in the direction of flow field. The mechanical properties of the ternary blends are increased when a proper amount of polyphosphazene is added. This is attributed to fine strand generation induced via the addition of polyphosphazene. Enhanced adhesion at the interface invokes better elongation in the ternary blends. However, mechanical properties deteriorate considerably when polyphosphazene content is 5 wt %. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Synthesis and characterization of readily soluble polyarylates derived from either 1,1‐bis(4‐hydroxyphenyl)‐1‐phenylethane or tetramethylbisphenol A and aromatic diacid chlorides
Authors: Liu Pengqing , Wu Ting , Shi Meiwu , Ye Guangdou , Xu Jianjun
Published: August 2010

A series easily soluble polyarylates were synthesized from either 1,1‐bis(4‐hydroxyphenyl)‐1‐phenylethane or tetramethylbisphenol A with various aromatic diacid chlorides by the two‐phase interfacial polycondensation. These polyarylates have the inherent viscositiesin the range of 0.36–0.97 dL/g, and their number‐average and weight‐average molecular weights determined by gel permeation chromatography are 14,200–43,200 and 31,900–102,500, respectively. All these polyarylates are readily soluble in a wide range of organic solvents, thus these polymers can be convenient to process into heat resistance films by cast, spin‐ or dip‐coating. The polyarylates have the glass transition temperatures in the range of 165.0–201.6°C. The pendent phenyl‐containing polyarylates reveal excellent thermal stability, and their initial degradation temperatures are all above 480°C and char yields at 700°C are 37.97–40.53% in nitrogen atmosphere. However, the polymers prepared from tetramethylbisphenol A have a large decrease in thermal stability, and their initial degradation temperatures in nitrogen are only about 440°C. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Shear and extensional rheology and flow‐induced orientation of carbon nanofiber/polystyrene melt composites
Authors: Miyazono Koki , Kagarise Christopher D. , Koelling Kurt W. , Mahboob Monon , Bechtel Stephen E.
Published: August 2010

The rheological behavior and morphology of polystyrene/carbon nanofiber (PS/CNF) composites in their melt phase have been characterized through experimental measurements. Viscosity measurements of the PS/CNF composites in the linear viscoelastic regime show the ratio of the transient extensional viscosity to the transient shear viscosity to be greater than three, the Trouton ratio. This behavior is due to differences in the flow‐induced orientation of CNFs in shear and extensional flow. The orientation development of the CNFs in shear and extensional flow was analyzed through a method utilizing transmission electron microscopy and was used to explain observed rheological phenomena. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Retracted: Microencapsulation of intumescent flame‐retardant agent and application to epoxy resins
Authors: Gao Ming , Wo Yaqi , Wu Weihong
Published: August 2010

The following article from the Journal of Applied Polymer Science, “Microencapsulation of intumescent flame‐retardant agent and application to epoxy resins,” by Ming Gao, Yaqi Wo, and Weihong Wu, published online on 25 August 2010 in Wiley Online Library (J. Appl. Polym. Sci. 2011, 119, 2025; http://onlinelibrary.wiley.com/doi/10.1002/app.32930/full), has been retracted by agreement between the authors, the journal's editors, and Wiley Periodicals, Inc. The retraction has been agreed because a pervasive misattribution of data resulted in fundamentally flawed experimental results, thus rendering the article's subsequent discussion and conclusions meaningless and misleading.
Decomposition rate control of PLLA plate by heat treatment
Authors: Nakagawa Masafumi , Teraoka Fumio , Sohmura Taiji
Published: August 2010

It is difficult to control the decomposition rate and the mechanical property of scaffolds after forming the poly(L‐lactide) (PLLA) scaffolds. The purpose of this study is to control the decomposition rate and mechanical properties of the PLLA plate after forming. We carried out accelerated decomposition experiments using the enzyme on the (PLLA) with various crystallinity, which were prepared by changing the heat treatment condition, and elucidated the relationship between the crystallinity and the decomposition rate. A high positive correlation was observed between the heat treatment temperature and the crystallinity. A high negative correlation was observed between the crystallinity and the decomposition rate. Using the obtained empirical formula, it became possible to calculate the required period to decompose a certain amount of the PLLA if the heat treatment temperature was known. Changing the crystallinity of the PLLA plate could arbitrarily control the decomposition rate of the PLLA plate after forming. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Fabrication of inorganic/polymer nanocomposite membranes containing very high silica content via in situ surface grafting reaction and reactive dispersion of silica nanoparticles: Proton conduction, water uptake, and oxidative stability
Authors: Kim Ju‐Young , Ohn Young‐Hwan , Ihn Kyo‐Jin , Lee Changhyun
Published: August 2010

In this study, we present a new fabrication process for proton exchange membranes based on inorganic/organic nanocomposite using in situ surface grafting reaction and reactive dispersion of silica nanoparticles in the presence of reactive dispersant, urethane acrylate nonionomer (UAN). Through in situ surface grafting reaction of silica nanoparticles, urethane acrylates were chemically introduced on the surface of silica nanoparticles, which were dispersed in DMSO solutions containing UAN and sodium styrene sulfonate (NaSS). After urethane linkage and copolymerization of NaSS, UAN and urethane acrylate moieties of silica nanoparticles, the solutions were converted to silica nanoparticle‐dispersed proton exchange membranes where silica particles were chemically connected with organic polymer chains. 5.89–29.45 wt % of silica nanoparticles could be dispersed and incorporated in polymer membranes, which were confirmed by transmittance electron microscopy (TEM) measurement. On varying weight % of silica nanoparticles dispersed within the membranes, water uptake and oxidative stability of nanocomposite membranes were largely changed, but membranes showed almost the same proton conductivity (greater than 10−2 S cm−1). At 5.89 wt % of silica nanoparticles, nanocomposite membranes showed the lowest water uptake and excellent oxidative stability compared to the sulfonated polyimide membranes fabricated by us. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Effect of controlled electron beam irradiation on the rheological properties of nanosilica‐filled LDPE‐EVA based thermoplastic elastomer
Authors: Hui S. , Mushtaq S. , Chaki T. K. , Chattopadhyay S.
Published: August 2010

The effect of controlled electron beam irradiation on the rheological properties of a model LDPE‐EVA thermoplastic elastomer (TPE) system filled with silica nanoparticles is explored in this article. The pristine silica particles were mixed with LDPE‐EVA system in molten condition by varying the sequence of addition and amount of nanosilica. In one composition, Si69 was used to improve the state of dispersion of nanosilica. The rheological behavior of irradiated TPE systems is influenced remarkably by irradiation dose, loadings of silica, variation of sequence, and addition of Si69. All filled TPE systems register an increase in elastic response with increasing frequency and with increase in irradiation dose. Upon irradiation, melt viscosity increases when compared with the unirradiated samples because of the crosslinking effect and improvements in interfacial bonding. The viscoelastic response varies markedly with the temperature. The radiation sensitizing effect of silica is reflected from the rheological data. The dynamic and steady shear rheological properties do not follow a simple correlation. Finally, the rheological behavior is correlated with the morphology of the irradiated systems processed at various shear rates. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Thermal stability and flame retardancy of polyester, cotton, and relative blend textile fabrics subjected to sol–gel treatments
Authors: Alongi Jenny , Ciobanu Mihaela , Tata Jennifer , Carosio Federico , Malucelli Giulio
Published: August 2010

Polyester (PET), cotton (COT), and two relative blend textile fabrics were treated by sol–gel processes. Tetraethoxysilane (TEOS) was used as inorganic precursor of silica phases; furthermore, different TEOS/H2O ratios were examined to explore the effect of the presence of SiO2 on the thermal and fire stability of the textile fabrics investigated. The distribution and dispersion of SiO2 were observed by means of scanning electronic microscopy (SEM). SEM magnifications showed the formation of a continuous silica film located in the neighboring fibers; furthermore, in the case of PET, such a film incorporated silica particles with an average diameter ranging between 0.2 and 6 μm. The thermal and thermooxidative stabilities of the treated samples were investigated by thermogravimetric analysis: after the sol–gel treatment, the degradation mechanism was modified both in nitrogen and in air, and the improvement in the thermal stability was attributed to the presence of silica, which played a protective role in the degradation of the textile fabrics. Finally, we investigated the combustion behavior of the textile fabrics by cone calorimetry, measuring the time to ignition, the heat release rate, and the relative peak. The former was found to depend on the type of fabric; the latter generally evidenced a remarkable decrease for all of the treated samples, up to 35% compared to the neat counterparts. This indicated that the sol–gel treatments improved the flame retardancy of the PET/COT fabrics. This conclusion was also confirmed by limiting oxygen index tests, which evidenced burning kinetics changes in the presence of the silica coating. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
The role of the disposition of the recycled polymer on the properties of films for greenhouses coverage
Authors: Dintcheva N. Tz. , La Mantia F. P. , Cascone M. , Balloni A.
Published: August 2010

Multilayer films, by using postconsumer materials in the central layer, i.e., multilayer composition: virgin polyethylene/postconsumer polymer/virgin polyethylene, allows to get a film for greenhouses coverage with good mechanical properties and photo‐oxidation resistance, similar to that of the films made from virgin material and certainly better than the photo‐oxidation resistance of the film made melt blending the virgin polyethylene and the postconsumer polymer. Moreover, the disposition of the postconsumer polymer containing oxygenated groups only in the central layer determines a significant slowdown of the photo‐oxidation process of the multilayer film although faster than of the pristine vPE film. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Bortezomib Plus Thalidomide for Newly Diagnosed Multiple Myeloma in China
Authors: Chen Shi‐Lun , Jiang Bin , Qiu Lu‐Gui , Yu Li , Zhong Yu‐Ping , Gao Wen
Published: August 2010

The aim of this Phase II study was to determine the efficacy and safety of combined bortezomib and thalidomide (VT) regime as initial treatment for newly diagnosed patients with multiple myeloma (MM) in China. Thirty‐four patients have been enrolled in this study and were planned to receive VT regime up to eight 21‐day cycles. Bortezomib (1.3 mg/m2) was given intravenously on days 1, 4, 8, and 11, while oral thalidomide (100 mg/day) was given on days 1 to 21. The primary end point was clinical response; the secondary end point was safety. Among 34 patients enrolled, 26 patients were able to complete the planned eight cycles of therapy. After eight cycles, the overall response rate was 100% (complete response 31%; near‐complete response 23%; partial response 42%; minimal response 4%). The best response occurred within the first four cycles in 96% of patients. Adverse events included hematologic (53%), peripheral neuropathy (38%), fatigue (35%), gastrointestinal (45%), and fever (32%). Grade 3 nonhematologic adverse events included four patients (12%) with renal failure associated with tumor lysis syndrome, one patient (3%) with peripheral sensory and motor neuropathy that improved with VT dose reduction, and one patient (3%) with hypotension. One patient (3%) experienced Grade 4 thrombocytopenia. No patient experienced deep venous thrombosis, while 1 patient (3%) died due to acute renal failure. In conclusion, Bortezomib in combination with thalidomide is a very effective regimen for newly diagnosed MM patients and the toxicities are manageable. Anat Rec 293:1679–1684, 2010. © 2010 Wiley‐Liss, Inc.
Coexpression of Serotonin and Nitric Oxide in the Raphe Complex: Cortical Versus Subcortical Circuit
Authors: Lu Yuefeng , Simpson Kimberly L. , Weaver Kristin J. , Lin Rick C.S.
Published: August 2010

Several lines of evidence have implicated a direct reciprocal interaction between serotonin and nitric oxide (NO). The goal of this investigation was, therefore, to examine the coexpression of tryptophan hydroxylase (TPH; the rate limiting enzyme for the synthesis of serotonin) and neuronal NO synthase (nNOS) in the ascending cortical projecting raphe nuclei (B6–B9 subgroups), when compared with the descending spinal cord projecting raphe nuclei (B1–B3 subgroups). Our data demonstrated that: (1) a significant number of raphe‐cortical projecting neurons was identified not only in the midline subgroup of dorsal raphe (B6, 7) but also in the median raphe (B8), as well as in the supralemniscal nucleus (B9); (2) serotonergic cortical projecting neurons from these three raphe nuclei exhibited a high (>80%) percentage of coexpression with nNOS immunoreactivity; (3) similarly, serotonin transporter immunoreactive fibers in the medial prefrontal cortex were also double‐labeled with nNOS immunoreactivity; (4) in contrast, the descending spinal cord projecting raphe nuclei revealed only TPH but not nNOS immunoreactivity. Our present findings suggest the existence of a direct interaction between serotonin and NO in the ascending cortical projecting raphe system. In contrast, a different strategy appears to operate the descending spinal cord projecting raphe system. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.
Functional and Histological Improvement of the Injured Spinal Cord Following Transplantation of Schwann Cells Transfected With NRG1 Gene
Authors: Zhang Jifei , Zhao Fusheng , Wu Geng , Li Yuezhen , Jin Xiudong
Published: August 2010

In this study, we implanted Schwann cells (SCs) transfected with Neuregulin 1 (NRG1) gene into rats with hemisection spinal cord injury, determined its effects on the repair of spinal cord injury and investigated the underlying mechanisms. Primary SCs were cultured, purified, and transfected with NRG1 gene. SCs and SCs transfected with NRG1 gene were implanted, respectively, into rats with hemisection spinal cord injury. Behavior, imaging, electrophysiology, and immuno‐histological analyses were performed to evaluate the effect of NRG1 gene‐transfected SCs on the repair of spinal cord injury. In vitro studies showed that NRG1 protein was highly expressed in SCs transfected with NRG1 gene. In addition, the receptors for NRG1, ErbB2, and ErbB4, were upregulated in a time‐dependent manner. NRG1‐transfected SCs secreted large amount of NRG1 proteins in vivo, which efficiently promoted the expression of ErbB2 and ErbB4 in the neurons and neuroglia cells. Moreover, the number of NSE‐ and GFAP‐positive cells was increased. After cell transplantation, many transplanted cells survived and migrated to the areas with spinal cord injuries. The injuries were recovered in all the experimental groups, but the most significant recovery was observed in the group of rats implanted with SCs transfected with NRG1 gene. We conclude that NRG1‐transfected SCs can significantly increase the effect on the repair of spinal cord injury. This repair effect is achieved via the upregulation of ErbB receptor in the target cells, increased proliferation of glial cells, and protection of neurons from apoptosis. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.
Endogenous Nitric Oxide Can Act as Beneficial or Deleterious in the Hypoxic Lung Depending on the Reoxygenation Time
Authors: Rus Alma , Molina Francisco , Peinado M. Ángeles , del Moral M. Luisa
Published: August 2010

Nitric oxide (NO) has been implicated in many pathophysiological situations in the lung, including hypoxia/reoxygenation. This work seeks to clarify the current controversy concerning the double protective/toxic role of endogenous NO under hypoxia/reoxygenation situations in the lung by using a nitric oxide synthase (NOS) inhibitor, in a novel approach to address the problems raised from assaults under such circumstances. A follow‐up study was conducted in Wistar rats submitted to hypoxia/reoxygenation (hypoxia for 30 min; reoxygenation of 0 h, 48 h, and 5 days), with or without prior treatment using the nonselective NOS inhibitor L‐NAME (1.5 mM, in drinking water). Lipid peroxidation, apoptosis level, protein nitration, in situ NOS activity and NO production (NOx) were analyzed. This is the first work to focus on the time‐course effects of L‐NAME in the adult rat lung submitted to hypoxia/reoxygenation. The results showed that after L‐NAME administration, in situ NOS activity was almost completely eliminated and consequently, NOx levels fell. Lipid peroxidation and the percentage of apoptotic cells rose at the earliest reoxygenation time (0 h), but decreased in the later period (48 h and 5 days). Also nitrated protein expression decreased at 48 h and 5 days posthypoxia. These results suggest that NOS‐derived NO exerts two different effects on lung hypoxia/reoxygenation injury depending on the reoxygenation time: NO has a beneficial role just after the hypoxic stimulus and a deleterious effect in the later reoxygenation times. Moreover, we propose that this dual role of NO depends directly on the producer NOS isoform. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.
Demethylation of Specific Wnt/β‐Catenin Pathway Genes and its Upregulation in Rat Brain Induced by Prenatal Valproate Exposure
Authors: Wang Zhongping , Xu Li , Zhu Xinping , Cui Weigang , Sun Yan , Nishijo Hisao , Peng Yuwen , Li Ruixi
Published: August 2010

Valproate (VPA) has been used for decades in the treatment of epilepsy and migraine. However, maternal administration of VPA during pregnancy increases susceptibility to autism spectrum disorders (ASDs) in the offspring. The aim of this study was to investigate the methylation modification and its effects on the activity of Wnt/β‐catenin pathway in the rat brain prenatally exposed to VPA. We exposed the rats in early pregnancy to VPA and found that the prenatal VPA exposure, in comparison with the prenatal vehicle exposure, induced demethylation in the promoter regions of wnt1 and wnt2, but not in those of Wnt inhibitory factor‐1 and Dickkopf 1, in the prefrontal cortexes and hippocampi of the offspring. Consequently, both mRNA and protein expression of wnt1 and wnt2 were increased. Furthermore, the activity of Wnt/β‐catenin pathway was upregulated, as indicated by the increased levels of β‐catenin, hence the growing expression of its target genes. This work suggested an epigenetic action via which VPA, when administered in early pregnancy, induced dysregulation of signaling pathway, further facilitating susceptibility to ASDs. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.
Regulation of Kidney Development by Shp2: An Unbiased Stereological Analysis
Authors: David Frank S. , Cullen‐McEwen Luise , Wu Xue Sue , Zins Stephen R. , Lin Julie , Bertram John F. , Neel Benjamin G.
Published: August 2010

Genes that regulate renal branching morphogenesis are likely to indirectly regulate nephron endowment, but few have been validated to do soin vivo.PTPN11, which encodes the nonreceptor protein tyrosine phosphatase Shp2, acts downstream of receptor tyrosine kinases to modulate the Ras‐MAPK pathway and has been implicated in branching morphogenesisin vitroand in invertebrates, and is therefore a candidatein vivoregulator of nephron number. In this work, heterozygous null mutant Shp2+/−mice at postnatal days 30–35 were compared with their wild‐type (WT) littermates using unbiased stereology to determine if, indeed, the former had decreased nephron number due to their 50% decrease in gene/protein dosage. Although there was a trend toward decreases in total glomerular (nephron) number and kidney volume in Shp2+/−mice compared with WT, neither difference was statistically significant (11310 vs. 12198 glomeruli,P= 0.22; 62.8 mm3vs. 66.0 mm3renal volume;P= 0.40). We conclude that loss of 50% gene/protein dosage ofPTPN11/Shp2 is insufficient to affect glomerular (and thereby nephron) number in mouse kidneysin vivo. Anat Rec, 2010. © 2010 Wiley‐Liss, Inc.