bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of mixer resident time on the overall moduli of polymer blends
Authors: Xie Zhimin , Zhang Dinghao , Sheng Jing , Song Kaixu 
Published: August 2002

AbstractThe overall moduli tensor of polymer blends is one of the most important characteristics of microscopic morphology development. This article focused on the analysis of dependence of the moduli on mixer resident time in terms of polypropylene–polystyrene (PP/PS) and polypropylene– polyamide1010 (PP/PA1010) blends. Tensile tests on the PP/PS and PP/PA1010 blends with a series of mixer resident times showed a marked change during the initial mixing stage, which may be due to the evolution of particle size and distribution from inhomogeneous to homogeneous. The two cases of periodic spatial distribution of the identical spherical particles were proposed to model the well‐ dispersed and slightly aggregating morphologies in the steady state. Based on the micromechanical model, the moduli of polymer blends were calculated by incorporating the influences of spatial distribution and Poisson's ratio of dispersed particles. Theoretical results indicated that spatial distribution should have little effect on the overall moduli in the steady state. Analysis of the blend system PP/PA1010 with and without compatibilizing agent showed good agreement between the calculations and experiments. Because the interfacial properties were not taken into account, the model gave an overestimate prediction for immiscible blends, like PP/PS for example. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 307–314, 2002
Morphology and mechanical properties of reactive compatibilized polystyrene/ethylene‐vinyl acetate‐vinyl alcohol blends
Authors: Tang L. W. , Tam K. C. , Yue C. Y. , Hu X. , Lam Y. C. , Li L. 
Published: August 2002

AbstractA reactive compatibilizer, styrene‐maleic anhydride (SMA) was used to compatibilize the blends of polystyrene (PS) and ethylene‐vinyl acetate‐vinyl alcohol (EVAOH), which was synthesized from ethylene‐vinyl acetate (EVA) using transesterification reaction. The compatibilized blends with different compositions were prepared using a twin‐screw extruder and injection molded into the required test specimens. Morphology of Charpy impact‐fractured surfaces, tensile, and impact properties of the blends were investigated. Fourier‐transform infrared spectroscopy (FTIR) was also applied for specific samples to elucidate the presence of the functional groups reaction necessary for reactive compatibilization. The results of the ternary PS/EVAOH/SMA blends illustrate that the addition of SMA as a compatibilizer slightly reduce the elongation at break. From the impact‐fractured surfaces of the blends, it is evident that the morphology developed sizable pores when SMA was added into the blends. This might be attributed to the residual octanol‐1, produced from the synthesis of EVAOH, as there is a possibility of a reaction between hydroxyl groups in the octanol‐1 and the anhydride groups in the SMA. This disrupted the stability of the morphology and resulted in the decrease in the elongation, and hence, the tensile toughness. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 209–217, 2002
Effects of vibration blending on the subsequent crystallization behavior of polycarbonate/polypropylene blends
Authors: Wang Kejian , Zhou Chixing , Yu Wei 
Published: August 2002

AbstractThe effects of blending in a novel vibration internal mixer on the subsequent multiple crystallization of 70/30 w/w polycarbonate (PC)/polypropylene (PP) were investigated by differential scanning calorimetry, wide‐angle X‐ray diffractogram, and microscopy. The vibration internal mixer was reformed from a conventional internal mixer through parallel superposition of an oscillatory shear on a steady shear. For this polypropylene‐minor phase blend, three possible crystallization peaks were observed. The crystallization behavior was sensitive to the sizes and the size distribution of the dispersed polypropylene droplets. Larger amplitude and/or higher‐frequency vibration produced more small droplets (<2 μm) and increased the number of medium droplets (2–8 μm) as a result of the spatially wider and temporally quicker variation of shear rate. The resulting subsequent low‐temperature crystallization peak became larger and shifted to lower temperature, and the intermediate‐temperature peak became obvious. On the contrary, the coalescence of small droplets, resulting from the heating treatment, weakened the low‐temperature peak but strengthened the intermediate‐temperature peak and rendered the high‐temperature peak to be wider. Mixing at the too high amplitude produced the unstable, partially cocontinuous phase morphology restricting the medium droplets and enlarging the surface area, such that the intermediate‐temperature crystallization peak did not appear. Multiple crystallization was related to phase morphology and the nucleation density as well as surface effects. Double‐fusion endotherms of the PP component were also observed, corresponding to the melting of different forms of polypropylene crystals. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 92–103, 2002
Studies on fibers spun from poly(vinyl alcohol‐b‐acrylonitrile) emulsions prepared by ultrasonic technique. II. Properties of the fibers
Authors: Xiao W. , Xiao L. , Xu K. , Chen K. , Xu X. 
Published: August 2002

AbstractThe moisture content of poly(vinyl alcohol‐b‐acrylonitrile) fibers decreases with an increasing hydrophobic AN content and crystallinity of the fibers; however, the copolymer fiber with 26.94% AN, drawn × 5, and heat‐treated at 200°C has a moisture content value slightly lower than that of commercial PVA fiber, but much higher than that of commercial PAN fiber. The block copolymer fibers have a water‐retention value higher than that of commercial PVA fiber, owing to the presence of voids in these fibers, and have a stronger wicking ability than that of commercial PVA, PAN fibers, and wool and cotton mainly due to the grooved surface and bulk porous morphology of the fibers. The tensile strength of the copolymer fibers with an appropriate AN content are lower than that of commercial PVA fiber, but higher than that of commercial PAN fiber and much higher than that of wool and cotton. The melting temperatures of the copolymer fibers increase with increasing heat‐treatment temperature. The copolymer fibers possess a lower peak cyclizing temperature than that of the PAN fiber and have a higher thermal stability than that of both PVA and PAN fibers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 989–994, 2001
Kinetic study by differential scanning calorimetry of the bulk copolymerization of 2‐hydroxyethylmethacrylate with ethyleneglycoldimethacrylate
Authors: Ajzenberg N. , Ricard A. 
Published: August 2002

AbstractThis article presents a kinetic study of the copolymerization of 2‐hydroxyethylmethacrylate (HEMA) with ethyleneglycoldimethacrylate (EGDMA). First, the rate constant of decomposition, kd, of azobisisobutyronitrile (AIBN) used to initiate the copolymerization was investigated. Then, the reactivity ratios, r1 and r2, of the monomers (HEMA and EGDMA), and the termination rate constant, kt, were determined. Rate constants were obtained by differential scanning calorimetry (DSC) experiments. The decomposition rate constant of AIBN follows an Arrhenius law in the temperature range 320–400 K. Copolymerizations were carried out in the pans of the DSC apparatus at 353 K. The reactivity ratios, determined after analysis of the mixture composition by gas chromatography, exploitation of the data using the Meyer and Lowry equation, and a numerical method, were found equal to r1 = 0.811 and r2 = 6.548. Also from the reaction rate obtained by DSC, the dependence of the termination rate constant with conversion and temperature has been established. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1220–1228, 2001
Blending poly(methyl methacrylate) and poly(styrene‐co‐acrylonitrile) as composite polymer electrolyte
Authors: Digar Mohanlal , Hung Shiue‐Liang , Wen Ten‐Chin 
Published: August 2002

AbstractA blend of poly(methyl methacrylate) (PMMA) and poly(styrene‐co‐acrylonitrile) (PSAN) has been evaluated as a composite polymer electrolyte by means of differential scanning calorimetry (DSC), Fourier transform infrared (FTIR) spectroscopy, ac impedance measurements, and linear sweep voltammetry (LSV). The blends show an interaction with the Li+ ions when complexed with lithium perchlorate (LiClO4), which results in an increase in the glass‐transition temperature (Tg) of the blends. The purpose of using PSAN as another component of the blend is to improve the poor mechanical properties of PMMA‐based plasticized electrolytes. The mechanical property is further improved by introducing fumed silica as inert filler, and hence the liquid electrolyte uptake and ionic conductivity of the composite systems are increased. Room‐temperature conductivity of the order of 10−4 S/cm has been achieved for one of the composite electrolytes made from a 1/1 blend of PSAN and PMMA containing 120% liquid electrolyte [1M LiClO4/propylene carbonate (PC)] and 10% fumed silica. These systems also showed good compatibility with Li electrodes and sufficient electrochemical stability for safe operation in Li batteries. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1319–1328, 2001
Transesterifications of poly(bisphenol A carbonate) with aromatic and aliphatic segments in ethylene terephthalate–caprolactone copolyester
Authors: Zhang Zhongping , Luo Xiaolie , Lu Yuchen , Ma Dezhu 
Published: August 2002

AbstractIn this article, transesterification of poly(bisphenol A carbonate) (PC) with a ethylene terephthalate–caprolactone copolyester at a weight ratio 50/50 (TCL50) was investigated by infrared spectroscopy (IR), proton nuclear magnetic resonance spectroscopy (1H‐NMR), and a model compound. The IR and 1H‐NMR results showed that transesterification occurred between PC and ethylene terephthalate (ET) segments in TCL50 and resulted in the formation of bisphenol A–terephthalate ester units as in the annealed blend of PC with the PET homopolyester. By comparison with a model compound, the new signal at 2.55 ppm in the 1H‐NMR spectrum confirmed the appearance of bisphenol A–caprolactone ester units resulting from the exchange reaction of PC with caprolactone (CL) segments. The 1H‐NMR analysis of the transesterification rates revealed that the reactions of PC with aromatic and aliphatic segments in TCL50 proceeded in a random or free manner. In addition, we separately examined the interchange reaction between a PC and poly(ε‐caprolactone) (PCL) homopolyester in an annealed blend. It was found that in the presence of a Ti compound catalyst the predominant reaction was a transesterification rather than a thermooxidative branching reaction. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1558–1565, 2001
Light‐scattering study of poly(hydroxy ester ether) in N,N‐dimethylacetamide solution
Authors: Cao X. , Sessa D. J. , Wolf W. J. , Willett J. L. 
Published: August 2002

AbstractStatic and dynamic light‐scattering techniques were used to study biodegradable thermoplastic poly(hydroxy ester ether) in N,N‐dimethylacetamide (DMAc). A weight‐average molecular weight MW = 6.4 × 104 g/mol, radius of gyration RG = 9.4 nm, second‐virial coefficient A2 = 1.05 × 10−3 mol mL/g2, translational diffusion coefficient D = 1.34 × 10−7 cm2/s, and hydrodynamic radius RH = 8.3 nm are reported. In addition, the effect of H2O on the polymer chain's conformation and architecture in a DMAc/H2O solution is evaluated. Results suggest that H2O makes the mixed solvent poorer as well as promotes polymer chain branching via intramolecular transesterification. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1737–1745, 2001
Preparation of polyethylene oxide/LixV2‐δO4‐δ nanocomposites
Authors: Xiao Y. , Hu K. A. , Yu Q. C. , Wu R. J. 
Published: August 2002

AbstractPolyethylene oxide (PEO)/LixV2‐δO4‐δ nanocomposites were prepared in aqueous solution. Characterization of the nanocomposites using thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), powder X‐ray diffraction (XRD), and Fourier transform infrared spectrum (FTIR) shows that polymer chains intercalate inorganic host lamella and exhibit lattice expansion along the stacking direction of 4.2 Å. A possible model for the structure of the nanocomposite is also provided. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2162–2166, 2001
Three‐dimensional dielectric characterization of polymer films
Authors: Patel Kaushal S. , Kohl Paul A. , Bidstrup‐Allen Sue Ann 
Published: August 2002

AbstractPolymer films are widely used in electronic packaging applications due to their low dielectric constant and ease of fabrication. These films often exhibit anisotropic electrical and thermomechanical properties, due to orientation of polymer chains, which need to be evaluated for performance and reliability modeling of electronic packages. This article presents a dual‐capacitor technique to measure the anisotropic dielectric permittivities of such films. Results are reported for in situ measurements for several spin‐coated polymeric films, some of which exhibit different permittivities in the in‐plane (x and y) and the through‐plane (z) directions (transversely isotropic), and free‐standing liquid crystalline Vectran films which exhibit orthotropic permittivities. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2328–2334, 2001
Effect of yielding on the viscoelastic response of amorphous glassy polymers
Authors: Drozdov Aleksey D. 
Published: August 2002

AbstractConstitutive equations are derived for the nonlinear viscoelastic behavior of amorphous glassy polymers. The model is based on the theory of cooperative relaxation in a version of the trapping concept. Stress–strain relations are applied to fit experimental data for polycarbonate in the sub‐yield and post‐yield regions. Fair agreement is demonstrated between observations and results of numerical simulation. It is revealed that yielding causes substantial changes in the energy landscape of amorphous polymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2383–2393, 2001
Synthesis and characterization of maleinized‐silylated low molecular weight guayule rubber (MASiGR)
Authors: Thames Shelby F. , Gupta Sandhya 
Published: August 2002

AbstractMaleinization followed by silylation of low molecular weight guayule rubber was accomplished for the first time via a two‐step process. Maleinization was first effected by grafting maleic anhydride onto guayule rubber under the influence of benzoyl peroxide catalyst to give maleinized guayule rubber (MAGR). The maleinized rubber was then further derivatized via hydrosilylation with dichloromethyl silane and chloroplatinic acid (Speier's catalyst) to give maleinized‐silylated guayule rubber (MASiGR). The silylated polymer (MASiGR) was further functionalized by reaction with ethanol or aqueous ammonia to produce ethoxysilane and silanol moieties, respectively. The products were characterized by Fourier transform infrared spectroscopy (FTIR), 1H‐, 13C‐, and 29Si‐ nuclear magnetic resonance spectroscopy (NMR). © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 754–761, 2001
Creating a macromolecular receptor by affinity imprinting
Authors: Vaidya A. A. , Lele B. S. , Kulkarni M. G. , Mashelkar R. A. 
Published: August 2002

AbstractA molecularly imprinted polymeric receptor for trypsin was synthesized by employing a novel technique that is a combination of affinity separation and molecular imprinting. An enzyme–inhibitor complex of trypsin and N‐acryloyl para‐aminobenzamidine was polymerized with acrylamide and N,N'‐methylene bis‐acrylamide. Template trypsin was extracted out to obtain an affinity‐imprinted polymer. Control experiments were performed to demonstrate the synergistic affinity‐imprinting effect. The percentage of crosslinker used was the crucial factor in determining the imprinting efficacy of the polymers. Imprinted polymer containing 50% crosslinker exhibited a linear Scatchard plot. Unlike non‐imprinted gel, the receptor exhibited almost exclusive recognition of trypsin in an individual batch experiment as well as from a mixture of trypsin and chymotrypsin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1075–1083, 2001
Long‐term mechanical and viscoelastic behavior of constitutive polymeric materials used for magnetic tapes
Authors: Weick Brian L. , Bhushan Bharat 
Published: August 2002

AbstractCreep‐compliance behavior of specially prepared magnetic tape materials was measured at elevated temperature levels to facilitate the use of a time–temperature superposition (TTS) process. This TTS process allowed for the construction of master curves at a reference temperature of 30°C, which were used to predict the long‐term viscoelastic behavior of the magnetic particle (MP) and metal‐evaporated (ME) tapes used in the study. The specially prepared samples allowed for the use of a rule of mixtures technique to determine the long‐term creep compliance of the front coat and back coat used for the magnetic tapes. To test the validity of this procedure, the front coat, substrate, and back coat data determined through separate experiments were used to calculate creep compliances of simulated tapes. These calculated creep‐compliance curves were then compared to measured data for the actual magnetic tapes. After determination and validation of the front coat, substrate, and back coat creep‐compliance data sets, they were used to determine strain distributions when the tapes are stored in a reel. Strain distributions were calculated for two cases, which reflect how tapes are stored in different drives: (1) the front coat (magnetic + nonmagnetic layer) is oriented away from the hub, and (2) the front coat is oriented toward the hub. Results showed that strain in the critical front coat of a tape is lower if it is stored with the front coat oriented toward the hub. In addition, the use of the creep‐compliance data showed that the MP tape front coat is more susceptible to creep than the ME tape front coat. The strain distributions in future magnetic tapes were also simulated by reducing the thickness and compliance of the layers. Results showed the importance of using lower compliance front coat, substrate, and back coat materials if thinner tapes are to be developed to increase the volume of information that can be stored in a magnetic tape reel. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1142–1160, 2001
Separation of Tc‐99m by means of radiation‐grafted membranes
Authors: Kamal H. , Hegazy El‐Sayed A. , El‐Adham K. , Geleel M. Abdel 
Published: August 2002

AbstractThe characterization and possibility of the practical use of different polymeric materials for the purpose of radioactive isotope separation from their wastes were studied. The influence of chemical treatment on the chelation or adsorption capacity at 25 °C was investigated. The equilibrium swelling of these polymers in distilled water at room temperature and the effect of solvent composition on the graft yield were also explored. In this study, the mechanical, chemical resistance and other properties for the grafted, untreated, and treated membranes were investigated. The performance of the membranes was studied as a function of time and degree of grafting. The effects of chemical treatment on the initial activity and separation of Tc‐99m have also been examined. The base polymer and degree of grafting have great influence on the Tc uptake. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1207–1215, 2001
Synthesis and properties of high oil‐absorptive network polymer 4‐tert‐butylstyrene–SBR–divinylbenzene
Authors: Zhou Mei Hua , Ha Chang‐Sik , Cho Won‐Jei 
Published: August 2002

Abstract4‐tert‐Butylstyrene–SBR–divinylbenzene (PBSD) was prepared by the graft crosslinking polymerization of 4‐tert‐butylstyrene (tBS) and divinylbenzene (DVB) onto unvulcanized SBR in the solution process using BPO as an initiator. The effects of reaction conditions, such as, solvent amount, SBR content, mol ratio of DVB to tBS, initiator concentration, reaction temperature, and reaction time on conversion, grafting efficiency, and gel fraction were examined. In present reaction system, a solvent amount 15.0 mL/g is the threshold of the gelation process. The oil absorbency was evaluated by the ASTM (F726‐81) method. The swelling rates, light resistance, and tensile strength of PBSD were investigated. It was found that the tensile strength is considerably better than that of 4‐tert‐butylstyrene–EPDM–divinylbenzene polymer (PBED). The highest oil absorbency of crosslinked PBSD was 57.76 g/g, and the largest swelling kinetic constant was 102.09 × 10−2 h−1. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1277–1285, 2001
Identification of deformation behavior in high‐thermal‐resistant poly(acrylonitrile‐butadiene‐styrene) (ABS)
Authors: Jar P.‐Y. Ben , Lee R. , Creagh D. C. , Konishi K. , Shinmura T. 
Published: August 2002

AbstractDeformation mechanisms in postfractured high‐thermal‐resistant poly(acrylonitrile‐butadiene‐styrene) (ABS) were investigated using transmission electron microscopy (TEM) and small‐angle X‐ray scattering (SAXS). Although crazes were clearly identified by TEM, they were not detectable by SAXS. This was possibly due to a short distance between sample and imaging plate in the SAXS set‐up and invisibility of craze fibril scattering from the postfractured samples. A rhomboid‐shaped SAXS pattern was obtained from ABS samples with high ductility but with no crazes shown in the TEM micrographs. It is believed that the rhomboid‐shaped SAXS pattern was generated from matrix shear yielding. The results show that a combination of TEM and SAXS enable us to distinguish crazing and shear yielding in the postfractured ABS. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1316–1321, 2001
Construction of cell‐compatible layer and culture of human umbilical vascular endothelial cells on porous polystyrene membranes
Authors: Gao Changyou , Li An , Yi Xiaosu , Shen Jiacong 
Published: August 2002

AbstractPorous polystyrene (PS) membranes with pore sizes ranged from nanometer scale to several decades' micrometers were fabricated by the thermally induced phase‐separation technique, and were characterized by scanning electron microscopy (SEM). Oxidation of PS membranes by concentrated sulfuric acid induced a decrease of the carbon amount on the membrane surfaces accompanying with an increase of the oxygen amount. The hydrophilic surfaces thus constructed proved quite effective to promote endothelial cell adhesion and growth. After culturing for 4 days, a confluent endothelial cells (ECs) layer was observed on nonporous PS membrane treated previously with sulfuric acid for 15 min at 28.5°C. The observation under SEM showed that ECs on the PS membrane surfaces at the fourth day were inversely proportional to the pore size: the smaller the pore size, the larger the amount of ECs on the membrane surfaces. It is supposed that the existence of pores on the membrane surface might generate some disadvantageous resistance to the spreading of cells. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3523–3529, 2001