bluuebunny/crossref_metadata_2025_split huggingface dataset:
Processing, crystallization, and dynamic mechanical analysis of high molar mass polysiloxane‐modified PP/CaCO3 composites
Authors: Renger C. J. , Burrows S. J. , Shanks R. A. 
Published: October 2004

AbstractA ternary system polypropylene (PP)/calcium carbonate (CaCO3)/high molar mass polysiloxane has been investigated with respect to its processing, crystallization, and dynamic mechanical properties. The filling level of PP varied from 2.5 vol % to 6.5 vol % CaCO3 and 0.6 vol % to 2.5 vol % polysiloxane, and the mixing was done in a single screw extruder. The polysiloxane molecules had different functionalities added (epoxy and methacrylate reactivity, respectively). However, the functionality did not influence processing, crystallinity, or mechanical properties. It was found that the polysiloxane molecules tended to surround the CaCO3 particles, thus forming a core‐shell structure. This structure was achieved without surface treatment of the filler. The polysiloxane also provided a lubrication effect in the melt and thus enabled an easier processing of the composite. A nucleating effect of the filler could be detected. The mechanical properties were similar to those found in other core‐shell structured samples, where the structure was achieved by surface treatment. It was found that the polysiloxane exhibited a lubricant effect only if it was mixed with PP together with CaCO3. If polysiloxane was added to the PP matrix alone, screw slippage occurred and the polysiloxane molecules agglomerated. The mechanical properties of these composites were similar to those of pure PP. No influence on the matrix crystallisation could be detected in this case. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3091–3098, 2001
Studies of syntheses and adsorption properties of chelating resin from thiourea and formaldehyde
Authors: Ni Caihua , Yi Changhai , Feng Zhiyun 
Published: October 2004

AbstractChelating resins are useful substances in industry because of their extraordinary adsorption properties for specific metal ions. In this study, a new type of chelating resin is synthesized simply by reaction between thiourea and formaldehyde. The synthetic conditions and the structure of the product are approached and the adsorbing capacities for 11 metal ions, adsorbing rates, and selectivities investigated. The results of the experiments show that the resin has high adsorbing capacities for Ag(I): 13.1 mmol/g, and for Au(III): 6.95 mmol/g. Adsorbing rates are close to 100% in dilute solution. Isothermal adsorbing study reveals that the adsorption is monomolecular layer adsorption process. It is hopeful for the resin to be used for concentrating and retrieving Ag(I) and Au(III) ions from their dilute solutions in industry. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3127–3132, 2001
Novel high‐Tg, high‐strength poly(aryl ether) containing quadrephenyl unit
Authors: Banerjee Susanta , Maier Gerhard , Salunke Arun , Madhra Mukesh 
Published: October 2004

AbstractA novel poly(aryl ether) was prepared by nucleophilic displacement of the fluorine atoms of a 2‐perfluoro‐activated bisfluoro monomer with bisphenol A. The polymer exhibited a weight average molar mass of 3.15 × 105 g mol−1 according to gel permeation chromatography. The poly(aryl ether) showed very good thermal stability, with only a 5% weight loss at 493°C according to thermogravimetric analysis under synthetic air, and it had a glass‐transition temperature at 223°C according to differential scanning calorimetry and at 243°C according to dynamic mechanical thermal analysis. The polymer was soluble in a wide range of organic solvents, including CHCl3, tetrahydrofuran, NMP, dimethylformamide (DMF), and toluene, and was insoluble in dimethyl sulfoxide and acetone. Transparent thin films of the polymer, cast from DMF, exhibited a tensile strength of 65 MPa, a modulus of 2.62 GPa, and an elongation at break of 130%. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3149–3156, 2001
Alcohol recovery with pervaporation: Effect of high 2‐butanol concentration
Authors: Shaban Habib I. , Ali Sami H. , Mathew Johnson 
Published: October 2004

AbstractPoly dimethyl siloxane (PDMS) membrane was used to separate a synthetic mixture consisting of isopropanol, ethanol, 2‐butanol, and n‐butanol using the pervaporation separation technique. These alcohols are found to occur in naphtha reformate as a result of vapor‐phase reaction of the alkenes in the presence of water and a catalyst. In this work the pervaporation separation efficiency of PDMS membrane toward different alcohols was evaluated by estimation of fluxes and separation factors at different temperatures and pressures. The coupling effect resulting from the presence of identical functional groups was investigated. The activation energies for the transport of each of these alcohols through the membrane were also evaluated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3164–3171, 2001
Study on dyeable polypropylene fiber and its properties
Authors: Yu Chengbing , Zhu Meifang , Shong Xingyuan , Chen Yanmo 
Published: October 2004

AbstractA disperse dyeable polypropylene fiber has been prepared by admixing polystyrene to the polymer prior to extrusion. Polystyrene has been synthesized at suitable molecule weight and narrow mol wt distribution. The dyeability, mechanical properties, shrinkage, degree of crystallinity, and orientation of pure polypropylene or the blend fibers with different amount of polystyrene were investigated. In addition, the structure of the blend containing 4 and 6% polystyrene was also studied to explain the interesting dyeing behavior of the blend fibers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3172–3176, 2001
Iosipescu shear deformation and fracture in model thermoplastic polyolefins
Authors: Xiang C. , Sue H.‐J. 
Published: October 2004

AbstractShear deformation and fracture behaviors in polypropylene (PP)‐based model thermoplastic polyolefins (TPOs) were investigated with the Iosipescu shear test. The shear deformation process was monitored in situ via video camera to obtain experimental shear stress–strain curves of model TPOs. Shear fracture mechanisms were studied with optical microscopy and scanning electron microscopy. Macroscopically, the cracks in neat PP propagated along the maximum shear plane, which indicated that mode‐II shear failure existed in neat PP. Microscopically, it was shown that shear fracture initiated in the form of partial, discontinuous inclined microcracks that later coalesced and formed the final continuous crack. The incorporation of rubber in PP could transform the shear fracture process into a stretching process in the shear damage zone. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3201–3214, 2001
Preparation and characterization of poly(vinyl alcohol)‐based magnetic nanocomposites. 1. Thermal and mechanical properties
Authors: López Daniel , Cendoya Ione , Torres F. , Tejada Javier , Mijangos Carmen 
Published: October 2004

AbstractCoFe2O4 magnetic nanoparticles were prepared by in situ precipitation and oxidation of Co2+ and Fe2+ within a sulfonated polystyrene resin. The nanometric particles were characterized by X‐ray diffraction. A ferrofluid was prepared from the CoFe2O4 mineralized polymer resin and water. Poly(vinyl alcohol) (PVA)‐based nanocomposite materials were obtained by mixing different amounts of ferrofluid (compositions ranging within 0–51 wt % of mineralized resin) with an aqueous solution of the polymer. The PVA composite materials were characterized by TGA, DSC, and stress–strain testing. The thermal and mechanical properties of PVA change with filler content, exhibiting an initial increase in these properties due to polymer–filler interactions. After a maximum value, at about 15 wt % of mineralized resin, the mechanical properties decrease probably due to particle aggregation which causes phase separation. The results obtained show that the nanoparticles are dispersed in the amorphous regions of the polymer, the crystalline zones remaining unaltered up to compositions as high as 30 wt %. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3215–3222, 2001
Melt spinning of metallocene catalyzed polypropylenes. I. On‐line measurements and their interpretation
Authors: Bond Eric Bryan , Spruiell Joseph E. 
Published: October 2004

AbstractThe melt spinning of metallocene catalyzed isotactic polypropylene resins was investigated. The details are presented for on‐line studies performed on six miPP resins with melt flow rates (MFRs) between 10 and 100 and a Ziegler–Natta catalyzed isotactic polypropylene resin with a MFR of 35 for comparison. The on‐line studies indicated that, as the molecular weight and polydispersity increased, crystallization occurred closer to the spinneret at higher crystallization temperatures and under lower spin line stresses. Further, as the spinning speed increased, crystallization occurred closer to the spinneret at higher crystallization temperatures because of increased stress in the spin line. These observations were interpreted in terms of an increased rate of crystallization caused by increased molecular orientation in the spin line with increasing molecular weight and increasing spinning speed. This “stress‐enhanced” crystallization was further interpreted in terms of an increased rate of crystal nucleation. It was further concluded that the narrower molecular weight distribution of metallocene resins was the primary factor that produced differences in the structure and properties of fibers spun from these resins compared to those of Ziegler–Natta catalyzed resins of similar weight‐average molecular weight or MFR. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3223–3236, 2001
Kinetic study on peroxidation of benzaldehyde by polymer‐immobilized cobalt‐EDTA complex
Authors: Wang Cheng‐Chien , Li Wen‐Sam , Cheng Shih‐Kai , Chen Chuh‐Yean , Chen Chuh‐Yung , Kuo Jen‐Feng 
Published: October 2004

AbstractPolymer‐immobilized cobalt‐EDTA complex was prepared by grafted copolymerization of methacrylic acid (MAA) and acrylonitrile (AN initiated by redox initiation of EDTA‐2Na (Ethylenediamine tetraacetic acid disodium salt) with ceric ion (Ce2+)). High yield and selectivity for peroxidation of benzaldehyde were obtained when using the polymer‐immobilized cobalt‐EDTA complex as a catalyst. With the concentration of benzaldehyde increasing, the concentration of perbenzoic acid was increased from 0.38M to 0.98M, but yield of perbenzoic acid decreased from 0.76M to 0.65M. With the amount of the polymer support increased, the yield of perbenzoic acid increased from 70% to 82%. The selectivity remained about 82% in the various amounts of the polymer support. The activation energy of peroxidation of benzaldehyde was 43.4 KJ/mole. The expression of the reaction rate was: ri = k[RCHO][polymer support]0.5. A mechanism for peroxidation of benzaldhyde catalysed by polymer‐immobilized cobalt‐EDTA complex was proposed in this investigation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3248–3257, 2001
Recycling of EPDM waste. I. Effect of ground EPDM vulcanizate on properties of EPDM rubber
Authors: Jacob Ceni , De P. P. , Bhowmick A. K. , De S. K. 
Published: October 2004

AbstractProcessing, cure characteristics, and mechanical properties of EPDM rubber containing ground EPDM vulcanizate of known composition were studied. Mooney viscosity increases and Mooney scorch time decreases by the addition of the ground vulcanizate. At higher loadings of the ground rubber, the maximum rheometric torque decreases. On addition of ground waste, stress–strain properties and tear resistance increase, whereas heat buildup marginally increases, resilience marginally decreases, low‐strain modulus remains constant, and abrasion resistance decreases. The interplay between the filler effect of the ground EPDM and the crosslink density changes of the EPDM matrix is believed to be the reason for the variation in mechanical properties. It is believed that sulfur migration occurs from the raw EPDM matrix (R‐EPDM) to the ground waste EPDM (W‐EPDM) particle while accelerator migration occurs from W‐EPDM to R‐EPDM. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3293–3303, 2001
Reactivity of cyclosiloxane with 3,3,4,4,5,5,6,6,6‐nonafluorohexyl group and its application to fluorosilicone synthesis
Authors: Furukawa Yutaka , Shin‐Ya Seiji , Miyake Haruhisa , Kishino Hideharu , Yamada Minoru , Kato Hitoshi , Sato Masakuni 
Published: October 2004

AbstractThe reactivity of cyclosiloxane with 3,3,4,4,5,5,6,6,6‐nonafluorohexyl group and its application to fluorosilicone synthesis were studied. In contrast to the polymerization of the commercially available 1,3,5‐tris(3,3,3‐trifluoropropyl)‐1,3,5‐trimethylcyclotrisiloxane (CF3–D3), the polymerization of 1,3,5‐tris(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)‐1,3,5‐trimethylcyclotrisiloxane (C4F9–D3) with sodium hydroxide yielded 1,3,5,7‐tetrakis(3,3,4,4,5,5,6,6,6‐nonafluorohexyl)‐1,3,5,7‐tetramethylcyclotetrasiloxane {[C4F9CH2CH2(CH3)SiO]4 (C4F9–D4)} as the major product, which was the result of the depolymerization by a backbiting mechanism. On the other hand, the polymerization of C4F9–D3 with trifluoromethanesulfonic acid yielded a polymer with good reproducibility, although the distribution of molecular weight tended to be bimodal. C4F9–D3 was also successfully copolymerized with octamethylcyclotetrasiloxane (D4). The properties of the obtained copolymers changed almost linearly with the amount of [C4F9C2H4(CH3)SiO] units, except for the surface tension. The surface tension of the copolymer containing more than 50% [C4F9C2H4(CH3)SiO] units by weight was almost as low as that of the homopolymer. When the copolymer containing 50% [C4F9C2H4(CH3)SiO] units by weight was examined for an antifoaming agent, it worked as effectively as the homopolymer in the toluene foaming system. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3333–3340, 2001
Cellulose phosphates as biomaterials. I. Synthesis and characterization of highly phosphorylated cellulose gels
Authors: Granja P. L. , Pouységu L. , Pétraud M. , De Jéso B. , Baquey C. , Barbosa M. A. 
Published: October 2004

AbstractThe present study concerns the investigation of a material expected to be biocompatible and able to promote bone regeneration. For this purpose, cellulose was chemically modified by phosphorylation. Once implanted, phosphorylated cellulose could promote the formation of calcium phosphates, thus having closer resemblance to bone functionality. In a previous investigation, the obtention and the preliminary characterization of cellulose phosphate gels were reported. In the present study, the synthesis by the H3PO4/P2O5/Et3PO4/hexanol method was optimized in terms of reaction parameters. The structure of materials was investigated by FTIR, Raman, and solid‐state 31P– and 13C–NMR spectroscopic studies, and X‐ray diffraction. Water swelling and stability to sterilization by gamma‐radiation were also assessed. It was demonstrated that the present method allows highly phosphorylated cellulose derivatives to be obtained. Cellulose triphosphates gels are described here for the first time. Products obtained were poorly crystallized monoesters, apparently not significantly affected by gamma sterilization and showed a high water swelling capability. Chemical bonding was confirmed by FTIR, Raman, and both 31P– and 13C–NMR spectroscopies. It was also shown that the H3PO4/P2O5/Et3PO4/hexanol method provides a versatile and interesting alternative route to some of the more widely used techniques for the phosphorylation of cellulose. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3341–3353, 2001
Cellulose phosphates as biomaterials. II. Surface chemical modification of regenerated cellulose hydrogels
Authors: Granja P. L. , Pouységu L. , Deffieux D. , Daudé G. , De Jéso B. , Labrugère C. , Baquey C. , Barbosa M. A. 
Published: October 2004

AbstractCellulose regenerated by the viscose process was previously investigated as an implantable material in orthopedic surgery. It was envisaged to take advantage not only of its good matching with mechanical properties of bone but also of its hydroexpansivity, therefore allowing a satisfactory fixation to hard tissue. Both the osteoconduction and the lack of osteoinduction of this material were demonstrated. Grafting of phosphate groups was then envisaged as the means to render cellulose more suitable for orthopedic applications by enhancing its bioactivity. In the present work, the previously optimized phosphorylation reaction was successfully adapted to the surface modification of regenerated cellulose. Modified materials were characterized by XPS, FTIR, and 31P MAS NMR spectroscopic studies, and contact angle measurements, revealing the chemical bond between phosphate groups and cellulose, as well as the hydrophilic nature of phosphorylated materials, which increases with increasing phosphate contents. Water swelling and resistance to gamma sterilization were assessed as well, showing that phosphorylated materials swell considerably in water and were not affected when sterilization was carried out under a nitrogen atmosphere. The increase in surface roughness attributed to chemical modification was demonstrated through laser rugosimetry measurements. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3354–3365, 2001
Effects of the molecular weight on the properties of thermoplastics prepared from soy protein isolate
Authors: Wu Qiangxian , Zhang Lina 
Published: October 2004

AbstractCommercial soy protein isolate (SPI) was fractionated into four fractions by an acidifying method from pH 5.7 to 4.5 with 2M HCl. A mixture of SPI with glycerin (50 g/100 g of dry SPI) was compression‐molded to obtain thermoplastic sheets. The weight‐average molecular weight (Mw) of the fractions, the structure, and the mechanical properties of the thermoplastic SPI sheets were investigated with light scattering, IR spectroscopy, wide X‐ray diffraction patterns, differential scanning calorimetry, ultraviolet spectroscopy, scanning electron microscopy, and tensile testing. After heating compression, the SPI sheets were transparent and exhibited a smooth and homogeneous structure. Moreover, the crystallinity degree of the thermoplastic SPI was obviously higher than that of the premix before compression because of the formation of intermolecular hydrogen bonding. The Mw's of the fractions were 1.17 × 105 to 3.21 × 105, and they increased with increasing pH value in fractionation. The mechanical properties and water resistance (R) of the SPI sheets increased with increasing Mw of the SPI fractions. The tensile strength and breaking elongation of the SPI sheets with an Mw value of 3.21 ×105 were 5.7 MPa and 135%, respectively, and the R value was 0.54 after immersion in water for 15 days. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3373–3380, 2001
Properties of thermoplastic polyurethane elastomers chemically modified by rosin
Authors: Sánchez–Adsuar M. S. , Papon E. , Villenave J.‐J. 
Published: October 2004

AbstractThermoplastic polyurethane elastomers (TPUs) are prepared including different amounts of rosin in their composition. Rosin is used either as an additive, mixed in the TPU solutions, or as a reactant in the chain‐extension step of polymer synthesis. The properties of the materials are studied using solution viscosity measurements, size‐exclusion chromatography, stress‐controlled rheometry, differential scanning calorimetry, wide‐angle X‐ray diffraction, and contact angle determinations. Rosin as an additive does not markedly change the polymer properties. On the contrary, the use of rosin in the chain‐extension step leads to sharp increases of viscosity and molar mass as well as improvements of rheological properties and changes in morphology: the crystalline regions are more affected (variations in the softening temperature and enthalpy) than the amorphous ones (quite constant glass‐transition temperature). The conclusion is that rosin acts as an actual chain extender and that it modifies the organization of both the hard and the soft segments of the polymers. Furthermore, the TPUs are used as raw materials of solvent‐based adhesives, which adhesion properties are characterized by T‐peel tests of PVC/TPU adhesive joints. Rosin as an additive cannot improve the low tack (initial adhesive strength) of TPU, although as a chain extender or cochain extender (together with butane diol) rosin allows development of significant initial adhesive strengths, while keeping a high level of actual (maximal) adhesive strength. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3402–3408, 2001
Synthesis and characterization of novel sulfobetaines derived from 2,4‐tolylene diisocyanate
Authors: Lee Wen‐Fu , Chen Chin‐Fu , Yen Shih‐Hsun 
Published: October 2004

AbstractNovel sulfobetaines were synthesized from two urethanes derived from 2,4‐tolylene diisocyanate (TDI) blocked with 2‐hydroxyethyl methacrylate (HEMA) and either N,N‐dimethylaminopropylamine (DMAPA) or N,N‐dimethylaminoethanolamine (DMAEA). The first‐stage reaction of TDI with HEMA was carried out in petroleum ether heterogeneously with the precipitation of the intermediate monoadduct product in the reaction solution. The second stage is a homogeneous reaction of the monoadduct with the blocking agent, DMAPA or DMAEA, in tetrahydrofuran (THF). In both reactions, an inhibitor, hydroquinone, and a catalyst, dibutyltin diacetate (DBDAc), were used. The tertiary amine urethanes were quaternized by 1,3‐propane sultone to form the two novel sulfobetaines. The results of the elemental analysis of those products along with their 1H‐NMR and IR spectra indicated that these materials were, indeed, the compounds expected. The products dissolved in strongly polar organic solvents. The copolymerization of these two monomers with comonomers such as styrene, methyl methacrylate, acrylamide, and HEMA was investigated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3447–3459, 2001
Effects of zone drawing on the structure of metallocene polyethylene
Authors: Berns David M. , Oyebode Elizabeth , Dair Benita , Cebe Peggy , Capel Malcolm 
Published: October 2004

AbstractThe influence of zone drawing on bulk properties and structure of metallocene polyethylene (m‐PE) is reported. Two different m‐PE materials were subjected to tensile stresses above the yield point by zone drawing in the temperature range from 50 to 100°C. Drawn materials were characterized by using small‐ and wide‐angle X‐ray scattering (SAXS, WAXS), molecular retraction, and small‐angle light scattering (SALS). Structural changes were studied as a function of drawing temperature, engineering stress, and draw ratio. WAXS showed strong crystalline orientation in drawn samples, and only the orthorhombic crystal modification was observed. SAXS showed lamellar orientation in drawn samples. At low drawing temperatures of 50 or 60°C, draw ratio increased as a step function of stress. There is a stress barrier, which must be exceeded before high‐draw ratios can be achieved at these temperatures. At drawing temperatures of 70°C or above, the barrier stress is low enough that draw ratio increases nearly linearly as a function of stress. Below the stress barrier, spherulitic structure is observed by small‐angle light scattering (SALS). Elongation occurs via deformation of the interspherulitic amorphous phase. Molecular retraction was low for these samples, indicating mostly plastic deformation of the amorphous material. Above the stress barrier, SALS showed that spherulites are destroyed. Elongation occurs via deformation of the intraspherulitic amorphous phase. Molecular retraction for these samples was high, indicating elastic deformation of the amorphous material. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 3492–3504, 2001