bluuebunny/crossref_metadata_2025_split huggingface dataset:
Studies of wool keratin by EPR spectroscopy
Authors: Pielesz Anna 
Published: July 2006

AbstractElectron 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

AbstractThis 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

AbstractThe 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

AbstractThe 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

AbstractA 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

AbstractThe 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

AbstractThe 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

AbstractCore–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

AbstractHeat 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

AbstractA 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

AbstractButadiene‐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

AbstractRecycled 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

AbstractA 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

AbstractThere 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

Abstract4‐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

AbstractIn 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

Abstractπ‐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