bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of dynamic elastic properties of wood‐filled polypropylene composites
Authors: Chauhan Shakti S. , Karmarkar Ajay , Aggarwal Pankaj
Published: July 2006

Dynamic modulus of elasticity (MoE) and shear modulus of wood‐filled polypropylene composite at various filler contents ranging from 10% to 50% was determined from the vibration frequencies of disc‐shaped specimens. Wood filler was used in both fiber form (pulp) and powder form (wood flour). A novel compatibilizer, m‐isopropenyl‐α,α‐dimethylbenzyl‐isocyanate(m‐TMI) grafted polypropylene with isocyanate functional group was used to prepare the composites. A linear increase in dynamic MoE, shear modulus, and density of the composite was observed with the increasing filler content. Between the two fillers, wood fiber filled composites exhibited slightly better properties. At 50% filler loading, dynamic MoE of the wood fiber filled composite was 97% higher than that of unfilled polypropylene. Halpin‐Tsai model equation was used to describe the changes in the composite modulus with the increasing filler content. The continuous improvement in elastic properties of the composites with the increasing wood filler is attributed to the effective reinforcement of low‐modulus polypropylene matrix with the high‐modulus wood filler. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1706–1711, 2006
Surface modification of PBO fibers by argon plasma and argon plasma combined with coupling agents
Authors: Liu Dandan , Hu Jian , Zhao Yaoming , Zhou Xuesong , Ning Ping , Wang Yi
Published: July 2006

The methods of argon plasma and argon plasma combined with coupling agents were employed to modify the poly[1,4‐phenylene‐cis‐benzobisoxazole] (PBO) fiber surface. The interfacial shearing strength (IFSS) of PBO fibers/epoxy resin was measured by the single fiber pull‐out test. The surface chemical structure and surface composition of PBO fibers were determined by FTIR and X‐ray photoelectron spectroscopy respectively. The morphology of the fiber surface was investigated by scanning electron microscopy and the specific surface area of the fibers was calculated by B.E.T. equation. Furthermore, the wettability of PBO fibers was confirmed by the droplet profile analysis method. The results showed that the elemental composition ratio of the fiber surface changed after the modification. The IFSS increased by 42 and 78% when the fibers were treated by argon plasma and argon plasma combined with the coupling agents, respectively. Meanwhile, the specific surface areas of the treated fibers were improved. In addition, compared with the modification of argon plasma, the modification of argon plasma combined with the coupling agents inhibited the attenuation phenomena of the IFSS and the wettability. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1428–1435, 2006
Flammability and thermal degradation behaviors of phosphorus‐containing copolyester/BaSO4 nanocomposites
Authors: Qu Ming‐Hai , Wang Yu‐Zhong , Liu Ya , Ge Xin‐Guo , Wang De‐Yi , Wang Chuan
Published: July 2006

A novel phosphorus‐containing copolyester (PET‐co‐DDP)/barium sulfate (BaSO4) nanocomposite was synthesized by in situ polymerization. The oxygen index values of the resulting nanocomposites decreased with increasing the content of BaSO4 nanoparticles, but their antidripping behaviors were improved obviously through the UL‐94 test. The flammability tests based on the cone calorimetry showed that the introduction of nano‐BaSO4 to the copolyester decreased remarkably the heat release rate and effective heat of combustion. The thermal oxidative decomposition behaviors of PET‐co‐DDP/BaSO4 nanocomposites were studied by a conventional dynamic thermogravimetric analysis in a flowing air atmosphere with a heating rate of 20°C/min. The activation energies determined from Kissinger method, Flynn‐Wall‐Ozawa method, and Friedman method had a same variation trend. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 564–570, 2006
Low molecular weight water‐soluble chitosans: Preparation with the aid of cellulase, characterization, and solubility
Authors: Li Jin , Du Yumin , Liang Hongbo
Published: July 2006

Preparation of water‐soluble chitosan (WSC) was made by treating partially N‐deacetylated chitosan with acetic anhydride in aqueous acetic acid. The optimal conditions of preparing WSC were determined on the basis of orthogonal tests. Low molecular weight WSC with broad molecular weight (600–1.5 kDa) were obtained by the depolymerization of WSC using cellulase at optimum condition of pH 4.5 and 60°C. The solubility of WSC in water and aqueous organic solvents was investigated in detail. Weight–average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of samples were measured by gel permeation chromatography. The structure of WSC and its degraded products were characterized by XRD, FTIR, and MALDI‐TOF MS. The decrease of molecular weight led to transformation of crystal structure and the increase of solubility, but the chemical structures of residues were not modified compared to WSC, which was not hydrolyzed. The solubility of the WSC in water and aqueous organic solvents increased with the decrease of molecular weight. The solubility of the WSC with low molecular weight was rather high even in aqueous dimethylacetamide and dimethylsulfoxide. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1098–1105, 2006
Studies of wool keratin by EPR spectroscopy
Authors: Pielesz Anna
Published: July 2006

Electron paramagnetic resonance (EPR) tests were conducted on four kinds of interrelated samples—natural undyed wool fibers (SW3, SW5), fibers dyed with model direct dyes (1W, 5W), fibers treated destructively with formic acid for descaling and dyed with the same dyes (K1W, K5W), and the dyes themselves (1%). For all samples, a radical signal of g = 2.007 was detected. The presence of Mn2+ and Fe3+ ions in the wool fiber structure was postulated. Modifications of disulfide regions of fiber matrix were also analyzed. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1459–1465, 2006
Effects of compatibilizer type and rubber‐wood sawdust content on the mechanical, morphological, and thermal properties of PVC/LDPE blend
Authors: Prachayawarakorn J. , Khamsri J. , Chaochanchaikul K. , Sombatsompop N.
Published: July 2006

This article aimed to investigate the mechanical, morphological and thermal properties of PVC/LDPE blend with and without the addition of compatibilizers. The effects of LDPE content, compatibilizer type and rubber‐wood sawdust loading on the properties of the blend were evaluated. The experimental results suggested that as the LDPE content was increased the mechanical properties of PVC‐LDPE blend progressively decreased due to poor interfacial adhesion. The continuity and compatibility between PVC and LDPE phases could be improved through three different types of compatibilizers which included chlorinated polyethylene (CPE) poly(methyl‐methacrylate‐co‐butyl acrylate) (PA20) and poly(ethylene‐co‐methacrylate) (Elvaloy). The PA20 was found to be the most suitable compatibilizer for the blend. A radical transfer reaction was proposed in this work to explain the structure and thermal changes of the PVC in PVC‐LDPE blend. The decomposition temperature of PVC in the blend decreased with the loading of the PA20 and the wood sawdust. As the sawdust content was increased the tensile and flexural moduli increased with considerable decreased in the tensile, flexural and impact strength, a slight improvement being achieved if the PA20 was incorporated in the composite. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 598–606, 2006
Synthesis and characterization of triglyceride‐based polyols and tack‐free coatings via the air oxidation of soy oil
Authors: Fornof A. R. , Onah E. , Ghosh S. , Frazier C. E. , Sohn S. , Wilkes G. L. , Long T. E.
Published: July 2006

The effect of time and temperature on the air oxidation of soybean oil in the absence of catalysts or added initiators was investigated. It was possible to divide the air oxidation of soybean oil into three regimes. The first regime of air oxidation resulted in insignificant change in the hydroxyl number. During this regime, it was proposed that natural antioxidants, which are present in raw soybean oil, were consumed and peroxide formation occurred. A drastic increase in hydroxyl number due to the formation and subsequent decomposition of peroxides marked the second regime of air oxidation. In the third regime of air oxidation, free radical crosslinking of the soybean oil occurred, and an insoluble gel was formed. The three regimes of air oxidation were used as a guide for the preparation of soy‐based polyols and crosslinked polymers. Crosslinked, tack‐free coatings were prepared from a metal catalyzed oxidation of soybean oil, where soybean oil and ambient oxygen were the only reactants. Higher temperatures (125°C) were more efficient than lower (50°C) for obtaining high gel fractions and tack‐free coatings. Cure of the coatings was expedited with exposure of the coating to UV irradiation after initial heating. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 690–697, 2006
Improving the antibacterial and UV‐resistant properties of cotton by the titanium hydrosol treatment
Authors: Xu Peng , Liu Xiaoyan , Wang Wei , Chen Shuilin
Published: July 2006

The titanium hydrosol was prepared and treated on the cotton fabrics to improve its antibacterial and UV‐resistant properties. The sol size and gel morphology on the fabric were characterized by Nanosizer, SEM, and AFM. The antibacterial reduction rate of the treated fabrics against Staphylococcus aureus and Escherichia coli reached above 95%, and the corresponding UV transmittance value of the treated fabrics decreased considerably, with a ultraviolet protection factor of 50 or excellent grade, and the protection was tested according to the Australian/New Zealand standards. In spite of 50 washing cycles, the antibacterial and UV‐resistant properties changed almost little because of the strong affinity between the gel particles and cellulose material. The strength tests of the treated fabrics also showed no negative effects from the treatment on the fabrics. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1478–1482, 2006
Surface properties of fluorinated hybrid coatings
Authors: Fabbri Paola , Messori Massimo , Montecchi Monica , Pilati Francesco , Taurino Rosa , Tonelli Claudio , Toselli Maurizio
Published: July 2006

A commercial perfluoropolyether containing alkoxysilane functionalities was employed to prepare organic–inorganic hybrid coatings by using the sol‐gel process in the presence of tetraethoxysilane. Contact angle analysis revealed a strong hydrophobic and oleophobic character of the coatings almost independently from the molecular weight of the starting fluorinated oligomer. Surface tension values were in the range of 14–16 mN/m, suggesting a preferential segregation of fluorinated segments onto the surface of the coating. Atomic force microscopy showed the presence very smooth surfaces permitting to neglect the contribution of the surface roughness to wettability. Friction coefficient values were markedly lower with respect to the value of uncoated glass substrate. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1483–1488, 2006
Pretilt angle of liquid crystal related to anisotropic polyimide layer thickness in a nematic liquid crystal cell
Authors: Gwag Jin Seog , Kim Jae Chang , Yoon Tae‐Hoon
Published: July 2006

The property of the unidirectional out‐of‐plane tilt angle in a nematic liquid crystal is investigated in view of van‐der‐Waals interaction between nematic liquid crystal molecules and three layers: the anisotropic polyimide layer, the isotropic polyimide layer, and the substrate layer. Dependence of the pretilt angle on the total thickness of the polyimide layer and the thickness of the anisotropic layer oriented by rubbing is estimated from experiment and theory. Our results show that the screening factor increases with the increase of the thickness of the isotropic layer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1505–1508, 2006
Influence of molecular structure on the rheology and thermorheology of metallocene polyethylenes
Authors: Hussein Ibnelwaleed A. , Hameed Tayyab , Williams Michael C.
Published: July 2006

The rheology of linear and branched metallocene polyethylenes (m‐PEs) was investigated. The linear metallocenes were prepared by gas‐phase polymerization, while the branched PEs were commercial resins. Molecular parameters such as Mw, branch type, and molecular weight distribution have influenced the viscoelastic behavior of both linear and branched PEs, whereas branch content (BC) had little influence on viscoelastic properties. Plots of log G′ versus log G″ revealed the effect of comonomer type on the viscoelastic behavior of m‐PEs. Flow activation energy (E) was found to be sensitive to both Mw and BC. Also, E for ethylene‐octene copolymers was observed to be always higher than the butene counterparts, which have been caused by the increase in molar volume of the repeating unit. For the effect of BC on E, different trends were observed for octene and butene m‐LLDPEs. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1717–1728, 2006
Preparation of core–shell poly(acrylic acid)/polystyrene/SiO2 hybrid microspheres
Authors: Wang Hualin , Shi Tiejun , Zhai Linfeng
Published: July 2006

Core–shell poly(acrylic acid)/polystyrene/SiO2 (PAA/PS/SiO2) hybrid microspheres were prepared by dispersion polymerization with three stages in ethanol and ethyl acetate mixture medium. Using vinyltriethoxysilane (VTEOS) as silane agent, functional silica particles structured vinyl groups on surfaces were prepared by hydrolysis and polycondensation of tetraethoxysilane and VTEOS in core stage. Then, the silica particles were used as seeds to copolymerize with styrene and acrylic acid sequentially in shell stage I and stage II to form PAA/PS/SiO2 hybrid microspheres. Transmission electron microscope results show that most PAA/PS/SiO2 hybrid microspheres are about 40 nm in diameter, and the silica cores are about 15 nm in diameter, which covered with a layer of PS about 7.5‐nm thick and a layer of PAA about 5‐nm thick. This core–shell structure is also conformed by Fourier transform infrared spectroscopy, X‐ray photoelectron spectroscopy, and differential scanning calorimetry. FTIR results show that silica core, PS shell, and PAA outermost shell are bonded by covalents. In the core–shell PAA/PS/SiO2 hybrid microsphere, the silica core is rigidity, and the PAA outermost shell is polarity, while the PS layer may work as lubricant owning to its superior processing rheological property in polymer blending. These core–shell PAA/PS/SiO2 hybrid microspheres have potential as new materials for polar polymer modification. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1729–1733, 2006
Correlation of 13C‐NMR analysis with fungal decay tests of polymeric structural wood constituents. II. Ground contact tests
Authors: Boonstra M. J. , Pizzi A. , Rigolet S.
Published: July 2006

Heat treatment at relatively high temperatures (ranging from 150°C to 260°C) appear to be an effective method to improve the durability of wood. This study investigated the reasons for the decay resistance of heat‐treated and untreated wood as composed of polymeric structural constituents by solid‐state CP‐MAS 13C‐NMR analysis after fungal exposure in ground contact. An industrially used two‐stage heat treatment method under relatively mild conditions (<200°C) was used to treat the samples. Fungal exposure in ground contact resulted in strong degradation of the carbohydrates (cellulose and hemicellulose) of treated and untreated Scots pine, Radiata pine, and Simaruba. Fungal attack of the carbohydrates appeared to occur mainly at C4, resulting in cleavage and eventually depolymerization of cellulose and hemicellulose. The CP‐MAS 13C‐NMR spectra of the heat‐treated wood revealed similarities but also clear differences after fungal exposure in ground contact with the untreated wood. In ground contact fungi appeared to attack the carbohydrates of heat‐treated wood at C1 and possibly at C4 in order to cleave and eventually depolymerize cellulose and hemicellulose. An attack on the out‐of‐the‐ring alcoholic group, CH2OH, of the carbohydrates of the heat‐treated wood was observed (particularly in treated Radiata pine). The fungus possibly tried to cleave the out‐of‐the‐ring CH2OH group on the main H‐bond fixing sites of the crystalline cellulose structure in order to open the cellulose crystalline structure to an amorphous structure to decrease its water repellency and facilitate enzymatic cellulose degradation; this was also observed, but to a lesser extent, in untreated Radiata pine and untreated Scots pine. The opening of the glucose pyranose ring in heat‐treated Simaruba after fungal exposure, not observed in the untreated wood, was remarkable, and the thermal degradation of alpha‐arabinofuranose during heat treatment indicated more extensive decay. Demethoxylation and ring opening of the aromatic structure of lignin were observed, especially in the heat‐treated Radiata pine, Douglas fir, and Simaruba. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 616–622, 2006
Poly(ethylene glycol‐β‐cyclodextrin) gels: Synthesis and properties
Authors: Cesteros Luis C. , Ramírez Camilo A. , Peciña Ainhoa , Katime Issa
Published: July 2006

A new hydrogel that combines poly(ethylene glycol) and β‐cyclodextrin has been synthesized. Both components are linked by using a diisocyanate (HDMI), first by end‐capping the poly(ethylene glycol) with isocyanate groups an then reacting it with β‐cyclodextrin, forming urethane links. Hydrogels of molar compositions (β‐cyclodextrin/poly(ethylene glycol)) ranging from 1/4 to 1/14 have been synthesized. These hydrogels swell quickly and their water contents depend upon temperature. The gels are temperature resistant and show an elastomeric behavior. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1162–1166, 2006
Preparation and characterization of anionically polymerized butadiene‐isoprene copolymer/clay nanocomposites
Authors: Zhang Zhenjun , Zhang Lina , Li Yang
Published: July 2006

Butadiene‐isoprene copolymer/montmorillonite (BIR/MMT) nanocomposites were synthesized successfully via in situ anionic polymerization. The results of transmission electron microscopy and X‐ray diffractometer showed that the clay layers were exfoliated and high reaction temperature benefited the exfoliation of layers in BIR/MMT. The polymerization still exhibited “living” characteristics with the addition of organophilic montmorillonite (OMMT). However, the contents of 1,2‐polybutadiene and 3,4‐polyisoprene of the copolymer decreased with the addition of OMMT, because of its absorption effect on N,N,N′,N′‐tetramethylethanediamine as revealed by 1H NMR. Moreover, it was observed that the glass‐transition temperature of the BIR/MMT nanocomposites also decreased when compared with the BIR copolymers. The thermal stability of the nanocomposites was improved, because of the barrier property of exfoliated clay layers. © 2006 Wiley Periodicals, Inc. J Appl PolymSci 102: 1167–1172, 2006
In situ microfibrillar‐reinforced composites of isotactic polypropylene/recycled poly(ethylene terephthalate) system and effect of compatibilizer
Authors: Taepaiboon Pattama , Junkasem Jirawut , Dangtungee Rapeephun , Amornsakchai Taweechai , Supaphol Pitt
Published: July 2006

Recycled poly(ethylene terephthalate) from waste bottles (hereafter, rPET) was used as an reinforcing material for isotactic polypropylene (iPP) based on the concept of in situ microfibrillar‐reinforced composites (iMFCs). Microfibers of rPET were successfully generated during melt‐extrusion and subsequent drawing and preserved in the final injection‐molded specimens. The effects of draw ratio, initial size of ground rPET flakes, and rPET content on morphological appearance of the extrudates and the as‐formed rPET fibers and mechanical properties of the as‐prepared iMFCs were investigated. The results showed that diameters of the as‐formed rPET fibers decreased with increasing draw ratio, and the initial size of ground rPET flakes did not affect the final diameters of the as‐formed rPET fibers nor the mechanical properties of the as‐prepared iMFCs. Flexural modulus, tensile modulus, and tensile strength of iPP/rPET iMFCs were improved by the presence of rPET microfibers and further improvement could be achieved by the addition of maleic anhydride‐grafted iPP (PP‐g‐MA), which was used as the compatibilizer. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1173–1181, 2006
Mechanical properties, water‐swelling behavior, and morphology of water‐swellable rubber prepared using crosslinked sodium polyacrylate
Authors: Liu Changsheng , Ding Junping , Zhou Lang , Chen Songhui
Published: July 2006

A novel water‐swellable rubber (WSR) has been prepared by blending chlorobutadiene rubber (CR), reactive clay and other additives with crosslinked sodium polyacrylate (CSP), which was modified by interpenetrating polymer networks (IPNs) technology with crosslinked P(AA‐co‐BA). The structure of WSR was characterized by scanning electron microscopy (SEM). The mechanical properties, water‐swelling ratio by mass, and the percentage loss of CSP in the WSR were investigated. The results showed that the modified CSP grains can be dispersed well in the CR, and that it resulted in increase of mechanical properties and water‐swelling ratio and in decrease of percentage loss of CSP, compared with the unmodified one. When the percentage content of crosslinked P(AA‐co‐BA) used to modify CSP reached 30%, the tensile strength, elongation at break, and water‐swelling ratio of WSR exhibited maximum value, and percentage loss of CSP exhibited minimum value. When the content of CSP in WSR was 30 phr, the tensile strength, elongation at break, and water‐swelling ratio and percentage loss of CSP of the WSR containing CSP modified were 7.7 MPa, 1530, 438, and 2.5%, respectively. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1489–1496, 2006
Effects of crystallinity on solid‐state polymerization of poly(ethylene terephthalate)
Authors: Duh Ben
Published: July 2006

There has been a widely held assumption that the solid‐state polymerization (SSP) rate of poly(ethylene terephthalate) (PET) decreases with increasing crystallinity. Several published articles that purported to prove this assumption were based on faulty experiments. Therefore, a proper experimental procedure has been used to study the true effects of crystallinity on the SSP of PET. The results show that, for PET in pellet and powder forms, the SSP rate increases with increasing crystallinity. This is because an increase in the crystallinity results in increased end‐group concentration in the amorphous phase, where SSP reactions take place, and decreased concentrations of inactive end groups trapped inside the crystals, thereby increasing the rates of end‐group collision and reactions. These positive effects outweigh the negative effect of the increased byproduct‐diffusion resistance because of the increase in crystallinity. As the particle size of PET is increased beyond a critical value of about 7 mm, the SSP rate actually decreases with increasing crystallinity because of the excessively increased byproduct‐diffusion resistance within the PET particles. However, this critical particle size is far greater than the pellet sizes of commercial PET resins. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 623–632, 2006
Tris(trimethylsilyl)methyl functionalized 4‐chloromethyl styrene polymers: Effects of side chain modification on polymer structure and glass transition temperature
Authors: Babazadeh Mirzaagha
Published: July 2006

4‐Chloromethyl styrene was copolymerized with various molar ratio of methyl methacrylate or ethyl methacrylate by solution free radical polymerization method, at 70 ± 1°C using α,α′‐azobis(isobutyronitrile) as an initiator. Then, very highly sterically hindered tris(trimethylsilyl)methyl substituent was covalently linked to the obtained copolymers with liberation of chlorine atoms. The structure of all polymers was characterized and confirmed by FT‐IR, 1H and 13C NMR spectroscopy techniques. The average molecular weight and glass transition temperature of polymers were determined using gel permeation chromatograph and differential scanning calorimeter instruments, respectively. Study of differential scanning calorimetry analyses showed that chemical modification of 4‐chloromethyl styrene copolymers with tris(trimethylsilyl)methyl substituents leads to an increase in the rigidity and glass transition temperature of polymers. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 633–639, 2006
Preparation and properties of T300 carbon fiber‐reinforced thermoplastic polyimide composites
Authors: Lu Yun‐Hua , Zhan Mao‐Sheng , Zheng Wen‐Hai
Published: July 2006

In this study, a series of T300 carbon fiber‐reinforced polyimide (CFRPI) composites were prepared by laminating premolding polyimide (PI) films with unidirectional carbon fiber (CF) layers. On the basis of PI systems design, the effect of CF volume fraction, processing conditions, and PI molecular structure on the properties of CFRPI composites was studied in detail. In addition, two kinds of nano‐particles, including carbon nano‐tube (CNT) and SiO2 were filled into the premolding PI films with different concentrations. And the effect of nano‐particles on the properties of CFRPI composites was also investigated. The surface characteristic of T300 CF was measured by X‐ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). The properties of premolding PI film and CFRPI composites were measured by dynamic mechanical analysis (DMTA), SANS testing machine, scanning electron microscopy (SEM), and so forth. These experimental results showed that the properties of CFRPI composites were mainly affected by the premolding PI film and molding condition. The change of CF volume fraction from 55% to 65% took little effect on the mechanical properties of CFRPI composites. In addition, the incorporation of nano‐particle SiO2 could further improve the properties of CFRPI composites, but CNT hardly improved the properties of CFRPI composites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 646–654, 2006
Synthesis of nitropyridine‐based π‐conjugated polymers and their chemical properties
Authors: Choi Byoung Ki , Yamamoto Takakazu
Published: July 2006

π‐Conjugated poly(3‐nitropyridine‐2,5‐diyl) (PPy‐3‐NO2), poly(3,3′‐dinitro‐2,2′‐bipyridine‐5,5′‐diyl) (PBpy‐3,3′‐diNO2), and a poly(arylene ethynylene) type polymer consisting of a 3,3′‐dinitro‐2,2′‐bipyridine unit (PAE‐1) were synthesized by Cu‐promoted Ullmann coupling reaction and Pd‐catalyzed coupling reaction. PPy‐3‐NO2 and PAE‐1 were soluble in organic solvents such as DMSO, DMF, and chloroform, and gel permeation chromatography analysis showed a number average molecular weight (Mn) of 9,300 and 12,300, respectively. PPy‐3‐NO2 gave intrinsic viscosity, [η], of 0.53 dL g−1 in DMF. PBpy‐3,3′‐diNO2 had somewhat lower solubility. The polymers exhibited a UV–vis peak at about 430 nm. PPy‐NO2 received electrochemical reduction at −1.5 V versus Ag+/Ag in acetonitrile, and gave an electrochemical redox cycle in a range from 0 to −1.1 V versus Ag+/Ag in an aqueous solution. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1763–1767, 2006
Polypropylene/clay nanocomposites: Combined effects of clay treatment and compatibilizer polymers on the structure and properties
Authors: Velasco J. I. , Ardanuy M. , Realinho V. , Antunes M. , Fernández A. I. , González‐Peña J. I. , Rodríguez‐Pérez M. A. , de Saja J. A.
Published: July 2006

Combined effects of clay treatment and compatibilizer polymers on the structure and properties of polypropylene/clay nanocomposites were studied. Dynamic mechanical analysis was used to analyze comparatively the dynamic mechanical response of different nanocomposites prepared from polypropylene and montmorillonite‐rich bentonite, and to relate such response with the material microstructure. Two different bentonites were used: a purified Spanish natural bentonite was organophillized by means of 11‐undecyl‐ammonium ion and a commercial bentonite organophillized with dimethyl dehydrogenated tallow ammonium ion. Three different polar copolymers were employed as compatibilizer agents in some of the formulations: maleic anhydride‐grafted polypropylene, maleic anhydride‐grafted poly(styrene‐co‐ethylenebutylene‐co‐styrene), and poly(ethylene terephthalate‐co‐isophthalate) (PET). To ascertain the microstructure characteristics in the nanocomposites, wide angle X‐ray diffraction, transmission electron microscopy, and differential scanning calorimetry techniques were used. The nanocomposites containing both bentonite organophillized with 11‐undecyl‐ammonium ion and PET, and maleated PP as compatibilizer system, were found to have the highest storage modulus and the smallest loss factor values, which was mainly due to the better clay platelets dispersion. The dynamic mechanical response of nanocomposites prepared with bentonite organophillized with dimethyl dehydrogenated tallow ammonium ion and maleated SEBS was strongly affected by the presence of this compatibilizer. The temperature of PP and α, β, and γ relaxations strongly depended on the interactions between the different phases in the nanocomposites. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1213–1223, 2006
Elastic properties of adhesive polymers. II. Polymer films and bond lines by means of nanoindentation
Authors: Konnerth Johannes , Jäger Andreas , Eberhardsteiner Josef , Müller Ulrich , Gindl Wolfgang
Published: July 2006

Seven different polymers used frequently as adhesives and/or matrix polymers in wood, wood composites, and natural fiber‐reinforced composites were studied by uniaxial tensile tests and nanoindentation. It was shown that the elastic modulus, the hardness, the creep factor, and the elastic‐, plastic‐, and viscoelastic work of indentation of the seven different polymers is essentially the same regardless whether the polymers were tested in the form of pure films or in situ, i.e., in an adhesive bond line with spruce wood. An excellent correlation was found between the elastic modulus measured by tensile tests and the elastic modulus measured by nanoindentation. In spite of the good correlation, the elastic modulus measured by nanoindentation is significantly higher than the elastic modulus measured by tensile tests. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102:1234–1239, 2006
Unexpected partial crystallization of an amorphous polyamide as induced by combined temperature and humidity
Authors: López‐Rubio Amparo , Gavara Rafael , Lagarón Jose M.
Published: July 2006

In this study, it is presented for the first time, the characterization of an amorphous polyamide after having been subjected to humid thermal conditions such as those typically applied in the industrial sterilization of packaged foods. From a fundamental point of view, it was fortuitously found that the combination of heat and moisture, with and without the assistance of pressure, was capable of inducing some crystallization in the otherwise amorphous polymer. Characterization of the crystallization process was carried out by differential scanning calorimetry, Fourier transform infrared, and simultaneous time‐resolved small and wide angle X‐ray scattering synchrotron experiments. The crystallization of the polymer began as characterized by wide angle X‐ray scattering and differential scanning calorimetry in the presence of humidity at ∼90°C and extended up to 120°C under autoclave conditions, and it is thought to be the result of heated moisture being able to disrupt the intense amide groups self‐association. Thus, the thermally activated molecular structure is thought to become plasticized by the combined presence of heat and water which, in turn, provoke sufficient segmental molecular mobility in the system to promote some degree of lateral order. Propertywise, the resulting consequences of this behavior are an increase in the barrier properties to oxygen and a reduction in water sorption. From an applied view point, it is suggested that this unexpected behavior could make this polymer of significant interest in retortable food packaging applications. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1216–1223, 2006
Influences of molecular weight and particle morphology on film processing properties of polyvinyl fluoride
Authors: Wang Jing , Lu Yafei , Li Hongfei , Yuan Huilin
Published: July 2006

To select a suitable kind of resin for preparing films, the melting point (Tm), thermal decomposition temperature (Td), and stretch property of polyvinyl fluoride (PVF) as a function of the viscosity–average molecular weight (Mη) were investigated. The results showed that Td and maximal stretch ratio of extrusion‐cast PVF films gradually increase with the increase of Mη. Tm also increases when Mη is below 400,000, but keeps invariable when Mη is beyond 400,000. Six different kinds of PVF resin samples in this article were classified into three types, according to their particle morphologies: (1) loose‐structured PVF (PVF‐A and G); (2) tight‐structured PVF (PVF‐F); and (3) intermediate‐structured PVF (PVF‐B, E, and H). The effects of the morphology on the solvent absorbability of PVF were studied. The results indicated that the loose‐structured PVF has better absorption capacity to solvent than does tight‐structured PVF. The processing temperature can be considerably reduced when N,N‐dimethylformamide (DMF) as a plasticizer was mixed with PVF, and the diminished magnitude depends on the absorption capacity of PVF to DMF. The evaporation of DMF is influenced by both molecular weight and particle morphology of PVF, and the final residue of DMF in the PVF/DMF mixture is dependent on the molecular weight of PVF. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 1780–1786, 2006
Temperature dependence of gel properties of two‐component physical gels
Authors: Mao Ching‐Feng
Published: July 2006

The cascade model for mixed gels developed by the author in a previous work is extended to describe the temperature‐dependent gel properties. The equilibrium constant of the association between component polymers is assumed to depend on temperature via a van't Hoff‐type equation. The temperature variation of the network structure and gel modulus is presented and discussed at different parameters such as enthalpy change per crosslink ΔH°, entropy change per crosslink ΔS°, functionality ratio s, and concentration ratio r. It is demonstrated that the model agrees reasonably well with the experimental data obtained from the rheological gelling for galactomannan/xanthan and glucomannan/xanthan mixed gels. However, the resulting model parameters are not consistent with those obtained from the concentration dependence study. A further investigation on the calorimetric thermogram of the glucomannan/xanthan mixed gel reveals that the gelling process involves an association reaction followed by a structural rearrangement, which is beyond the scope of this work. Finally, the cascade model is shown to be consistent with the Eldridge–Ferry equation. It is also demonstrated that the sol–gel behavior of the galactomannan/xanthan mixed gel follows the Eldridge–Ferry relationship, but the calculated melting enthalpy is composition‐dependent, contrary to the assumption made in the cascade model. This discrepancy is due to the self‐association of xanthan when xanthan is present in excess amounts. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 663–673, 2006
Ab‐initio Calculations of Titanium Solubility in NaAlH4 and Na3AlH6.
Authors: Lee Eung‐Kyu , Cho Young Whan , Yoon Jong Kyu
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
NaIn(CrO4)2×2H2O, the First Indium(III) Member of the Kroehnkite Family.
Authors: Kolitsch Uwe
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Antiferromagnetic Ordering with an Anisotropy Reversal in USn0.5Sb1.5.
Authors: Tran V. H. , Bukowski Z. , Stepien‐Damm J. , Troc R.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Characterization of Amorphous LiNiVO4 Thin‐Film Anode Grown by Pulsed Laser Deposition.
Authors: Tang S. B. , Xia H. , Lai M. O. , Lu L.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
[Sb11]3‐ and [As11]3‐: Synthesis and Crystal Structure of Two New Ammoniates Containing Trishomocubane‐Like Polyanions.
Authors: Hanauer Tobias , Korber Nikolaus
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The Zintl Ion [Pb10]2‐: A Rare Example of a Homoatomic closo Cluster.
Authors: Spiekermann Annette , Hoffmann Stephan D. , Faessler Thomas F.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Novel Cobalt(II)—Molybdenum(V) Phosphate Organic—Inorganic Hybrid Polymer.
Authors: Shi Fa‐Nian , Amleida Paz Filipe A. , Girginova Penka I. , Nogueira Helena I. S. , Rocha Joao , Amaral Vitor S. , Klinowski Jacek , Trindade Tito
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis, Structure and Optical Limiting Effect of a Novel Inorganic—Organic Hybrid Polymer Containing Mixed Chains of Copper(I)/Iodine.
Authors: Li Hao‐Hong , Chen Zhi‐Rong , Li Jun‐Qian , Zhan Hong‐Bing , Zhang Wen‐Xuan , Huang Chang‐Cang , Ma Cheng , Zhao Bin
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Crystal Chemistry and Crystallography of the SrLn2CuO5 (Ln: Lanthanides) Phases.
Authors: Wong‐Ng W. , Haugan T. , Kaduk J. A. , Young R. A. , Yang Z. , Jang M. H. , Luong M.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Mass Spectra of New Functionally Substituted Heterocycles. Part 5. First Example of McLafferty Rearrangement in the Series of 5‐(1‐Ethoxyethoxy)‐2,3‐dihydropyridines and 3‐(1‐Ethoxyethoxy)pyridines Derived from α‐Lithiated 1‐(1‐Ethoxyethoxy)allene and Methoxymethyl Isothiocyanate.
Authors: Klyba L. V. , Nedolya N. A. , Shlyakhtina N. I. , Zhanchipova E. R.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
A Highly Enantioselective Abiotic Receptor for Malate Dianion in Aqueous Solution.
Authors: Gonzalez‐Alvarez Almudena , Alfonso Ignacio , Diaz Pilar , Garcia‐Espana Enrique , Gotor Vicente
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Direct Enantio‐ and Diastereoselective Mannich Reactions of Malonate and β‐Keto Esters with N‐Boc and N‐Cbz Aldimines Catalyzed by a Bifunctional Cinchonine Derivative.
Authors: Tillman A. Louise , Ye Jinxing , Dixon Darren J.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Nickel‐Catalyzed Asymmetric α‐Arylation of Ketone Enolates.
Authors: Chen Guoshu , Kwong Fuk Yee , Chan Hoi On , Yu Wing‐Yiu , Chan Albert S. C.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Dual‐Function Cinchona Alkaloid Catalysis: Catalytic Asymmetric Tandem Conjugate Addition—Protonation for the Direct Creation of Nonadjacent Stereocenters.
Authors: Wang Yi , Liu Xiaofeng , Deng Li
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthesis of a New Polyheterocyclic System — Pyrazolo[5′,1′:2,3]pyrimido[1,6‐a]benzimidazole.
Authors: Dzvinchuk I. B. , Lozinskii M. O.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Cycloacylation of Phenylsulfonyl‐N‐R‐thioacetamides by Compounds Containing an Activated Multiple Bond.
Authors: Britsun V. N. , Esipenko A. N. , Lozinskii M. O.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
New Simple and One‐Pot Synthetic Routes to Polyfunctionally Substituted Imidazo[1,2‐a]pyridines, Pyrido[1,2‐a]pyrimidines, Pyrido[1,2‐a]‐1,3‐diazepines, and Imidazo[1,2‐a]pyrimidines
Authors: Hammouda M. , Zeid Z. M. Abou , Metwally M. A.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Highly Facile Homogeneous Epoxidation of Olefins Using Oxo‐diperoxo Tungstate(VI) Complex as Catalyst, Bicarbonate as Co‐Catalyst and Hydrogen Peroxide as a Terminal Oxidant.
Authors: Maiti Swarup K. , Dinda Subhajit , Gharah Narottam , Bhattacharyya Ramgopal
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Novel and Highly Selective Conversion of Alcohols, Thiols and Trimethylsilyl Ethers to Alkyl Nitrites with 2,4,6‐Trichloro[1,3,5]triazine/n‐Bu4NNO2 System.
Authors: Akhlaghinia Batool , Roohi Elham
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Amine‐Catalyzed Aldol Condensation in the Presence of Lithium Perchlorate.
Authors: Arnold Aline , Markert Morris , Mahrwald Rainer
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Modified (NHC)Pd(Allyl)Cl (NHC = N‐Heterocylic Carbene) Complexes for Room‐Temperature Suzuki—Miyaura and Buchwald—Hartwig Reactions.
Authors: Marion Nicolas , Navarro Oscar , Mei Jianguo , Stevens Edwin D. , Scott Natalie M. , Nolan Steven P.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
DDQ‐Mediated Direct Cross‐Dehydrogenative‐Coupling (CDC) Between Benzyl Ethers and Simple Ketones.
Authors: Zhang Yuhua , Li Chao‐Jun
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Synthetic Applications of Ethyl 3‐Bromodifluoromethyl‐3‐benzyloxy‐acrylate as a gem‐Difluorination Building‐Block: Its Reactions with Aldehyde and Epoxide.
Authors: Peng Weimin , Zhao Jingwei , Zhu Shizheng
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
One‐Pot Wittig Olefination—Suzuki Reaction — The Compatibility of Conjugated Phosphoranes in Pd(0) Catalyzed C—C‐Bond Forming Reactions.
Authors: Thiemann Thies , Watanabe Masataka , Tanaka Yasuko , Mataka Shuntaro
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
In situ Generation of 3,3,3‐Trifluoropropanal and Its Use for Carbon—Carbon Bond‐Forming Reactions.
Authors: Yamazaki Takashi , Kobayashi Rei , Kitazume Tomoya , Kubota Toshio
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Organocatalytic Enantioselective Michael Addition of Thioacetic Acid to Enones.
Authors: Li Hao , Zu Liansuo , Wang Jian , Wang Wei
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Rh‐Catalyzed Enantioselective [2 + 2] Cycloaddition of Alkynyl Esters and Norbornene Derivatives.
Authors: Shibata Takanori , Takami Kyoko , Kawachi Ai
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
Metal‐Mediated Efficient Synthesis, Structural Characterization, and Skeletal Rearrangement of Octasubstituted Semibullvalenes.
Authors: Wang Chao , Yuan Jian , Li Guotao , Wang Zitao , Zhang Shiwei , Xi Zhenfeng
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
An Efficient and Product Selective Reduction of Azoxyarenes into Azoarenes or Hydrazoarenes by Tin/Hydrazine Hydrate.
Authors: Nanjundaswamy H. M. , Pasha M. A.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
The α‐Arylation of α‐Bromo‐ and α‐Chloroenones Using Palladium‐Catalyzed Cross‐Coupling.
Authors: Banks James C. , Van Mele David , Frost Christopher G.
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.
β‐Alkyl‐α‐allylation of Michael Acceptors Through the Palladium‐Catalyzed Three‐Component Coupling Between Allylic Substrates, Trialkylboranes, and Activated Olefins.
Authors: Patil Nitin T. , Huo Zhibao , Yamamoto Yoshinori
Published: July 2006

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.