bluuebunny/crossref_metadata_2025_split huggingface dataset:
Photoinitiated, inverse emulsion polymerization of acrylamide: Some mechanistic and kinetic aspects
Authors: Liu Lianying , Yang Wantai 
Published: January 2004

AbstractThe kinetics of photoinitiated, inverse emulsion polymerization of acrylamide with 2,2‐dimethoxy‐2‐phenylacetophenone (DMPA) as a photoinitiator was investigated under three different cases. First, in a quartz reactor transparent to full UV light, the polymerization rate (Rp) increased and then decreased with the change of initiator order from 0.27 to a negative value when the DMPA concentration was increased, and it was particularly unusual that monomer orders at different DMPA concentrations were lower than the first. Second, for polymerization without DMPA in a quartz reactor, the dependence of Rp on monomer concentration was similar to that of Rp on initiator concentration in the aforementioned case. Third, when polymerization was carried out in a Pyrex reactor where the far UV light was filtered, a peak rate was also observed, and initiator orders varied from 0.24 to a negative value; however, under this case monomer orders at different initiator concentrations were greater than the first. These results indicated that the effect of absorbance often observed in bulk or solution photopolymerization also existed in this system, and the self‐initiation of monomer had some influence on polymerization, and the role of primary radical termination could not be neglected, as evidenced by kinetic analysis. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 846–852, 2004
Photopolymerization of acrylates without photoinitiators with short‐wavelength UV radiation: A study with real‐time fourier transform infrared spectroscopy
Authors: Scherzer T. 
Published: January 2004

AbstractThis article reports on the UV photopolymerization of acrylates without photoinitiators. Initiation of the reaction was achieved by direct excitation of the acrylates during irradiation with short‐wavelength UV light by use of the 222‐nm emission of a KrCl* excimer lamp. The reactivity of various acrylates was studied by real‐time Fourier transform infrared–attenuated total reflection spectroscopy. The rate and the extent of the reaction within the layer were strongly dependent on the depth of penetration of UV light, which was determined by the molar extinction coefficient of the acrylate. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 894–901, 2004
Micron‐granula polyolefin with self‐immobilized nickel and iron diimine catalysts bearing one or two allyl groups
Authors: Jin Guoxin , Zhang Dao 
Published: January 2004

AbstractSelf‐immobilized nickel and iron diimine catalysts bearing one or two allyl groups of [ArNC]2(C10H6)NiBr2 [Ar = 4‐allyl‐2,6‐(i‐Pr)2C6H2] (1), [ArNC(Me)][Ar′N C(Me)]C5H3NFeCl2 [Ar = Ar′ = 4‐allyl‐2,6‐(i‐Pr)2C6H3, Ar = 2,6‐(i‐Pr)2C6H3, and Ar′ = 4‐allyl‐2,6‐(i‐Pr)2C6H3] were synthesized and characterized. All three catalysts were investigated for olefin polymerization. As a result, these catalysts not only showed high activities as the catalyst free from the allyl group, such as [ArNC]2C10H6NiBr2 (Ar = 2,6‐(i‐Pr)2C6H2)], but also greatly improved the morphology of polymer particles to afford micron‐granula polyolefin. The self‐immobilization of catalysts, the formation mechanism of microspherical polymer, and the influence on the size of the particles are discussed. The molecular structure of self‐immobilized nickel catalyst 1 was also characterized by crystallographic analysis. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1018–1024, 2004
Morphology and nonisothermal crystallization of in situ microfibrillar poly(ethylene terephthalate)/polypropylene blend fabricated through slit‐extrusion, hot‐stretch quenching
Authors: Li Zhong‐Ming , Yang Wei , Li Liang‐Bin , Xie Bang‐Hu , Huang Rui , Yang Ming‐Bo 
Published: January 2004

AbstractThis study describes the morphology and nonisothermal crystallization kinetics of poly(ethylene terephthalate) (PET)/isotactic polypropylene (iPP) in situ micro‐fiber‐reinforced blends (MRB) obtained via slit‐extrusion, hot‐stretching quenching. For comparison purposes, neat PP and PET/PP common blends are also included. Morphological observation indicated that the well‐defined microfibers are in situ generated by the slit‐extrusion, hot‐stretching quenching process. Neat iPP and PET/iPP common blends showed the normal spherulite morphology, whereas the PET/iPP microfibrillar blend had typical transcrystallites at 1 wt % PET concentration. The nonisothermal crystallization kinetics of three samples were investigated with differential scanning calorimetry (DSC). Applying the theories proposed by Jeziorny, Ozawa, and Liu to analyze the crystallization kinetics of neat PP and PET/PP common and microfibrillar blends, agreement was found between our experimental results and Liu's prediction. The increases of crystallization temperature and crystallization rate during the nonisothermal crystallization process indicated that PET in situ microfibers have significant nucleation ability for the crystallization of a PP matrix phase. The crystallization peaks in the DSC curves of the three materials examined widened and shifted to lower temperature when the cooling rate was increased. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 374–385, 2004
Unique morphological and thermal behaviors of reorganized poly(ethylene terephthalates)
Authors: Wei Min , Bullions Todd A. , Rusa Cristian C. , Wang Xingwu , Tonelli Alan E. 
Published: January 2004

AbstractBulk poly(ethylene terephthalate) PET has been reorganized both morphologically and conformationally by processing from its inclusion complex (IC) formed with γ‐cyclodextrin (CD). In the narrow channels of its γ‐CD‐IC crystals the included guest PET chains are isolated from neighboring PET chains and the ethylene glycol (EG) units adopt the highly extended g±tg∓ kink conformations, whose cross‐sectional diameters are ∼80% of the diameter of the fully extended, all‐trans crystalline PET conformer, though they are nearly (∼95%) as extended. When the highly extended, unentangled guest PET chains are coalesced from their γ‐CD‐IC crystals by exposure to hot water, host γ‐CDs are removed and the PET chains are presumably consolidated into a bulk sample with a morphology and constituent chain conformations not normally found in PET samples solidified from their randomly coiling, possibly entangled, disordered melts and solutions. Observations by polarized light and atomic force microscopies provide visual evidence for widely different semicrystalline morphologies developed in coalesced and as‐received PETs when crystallized from their melts, with possibly chain extended, small crystals and spherulitic, chain‐folded, large crystals, respectively. DSC observations reveal that coalesced PET is rapidly crystallizable from the melt, while as‐received PET is slow to crystallize and is easily quenched into a totally amorphous sample. Analyses of 13C‐NMR data strongly indicate that the PET chains in the noncrystalline regions of the coalesced sample remain predominantly in the highly extended kink conformations, with g±tg∓ EG units, which are required by their inclusion into PET‐γ‐CD‐IC crystals, while the predominantly amorphous PET chains in the as‐received sample have high concentrations of gauche± CH2CH2 and trans OCH2,CH2O EG bond conformations. 13C‐NMR T1(13C) and T1ρ(1H) relaxation studies show no evidence of a glass transition for coalesced PET, while the as‐received sample shows abrupt changes in both the MHz [T1(13C)] and kHz [T1ρ(1H)] motions at T ∼ Tg. Preliminary observations of differences in their macroscopic properties are attributed to the very different morphologies and conformations of the constituent chains in these PET samples. Apparently the kink conformers in the noncrystalline regions of coalesced PET are at least partially retained for extended periods even in the melt and are rapidly crystallized upon cooling. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 386–394, 2004
Temperature‐responsive linear polyelectrolytes and hydrogels based on [2‐(methacryloyloxy)ethyl] trimethylammonium chloride and N‐isopropylacrylamide and their complex formation with potassium hexacyanoferrates (II, III)
Authors: Khutoryanskiy V. V. , Nurkeeva Z. S. , Mun G. A. , Sergaziyev A. D. , Kadlubowski S. , Fefelova N. A. , Baizhumanova T. , Rosiak J. M. 
Published: January 2004

AbstractWater‐soluble temperature‐responsive polyelectrolytes and hydrogels have been synthesized by γ‐radiation copolymerization of [2‐(methacryloyloxy)‐ethyl]trimethylammonium chloride with N‐isopropylacrylamide. Complex formation of soluble copolymers with potassium hexacyanoferrates (II, III) was studied in aqueous solutions. It was shown that, depending on the concentration and temperature, the formation of soluble or insoluble polycomplexes is observed. The hydrogels show good ability to absorb potassium hexacyanoferrates (II, III) from aqueous solutions. Sorption ability of hydrogels depends on the content of cationic monomer in copolymer and the nature of coordination ion. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 515–522, 2004
Melt spinning and laser‐heated drawing of a new semiaromatic polyamide, PA9‐T fiber
Authors: Jalal Uddin Ahmed , Ohkoshi Y. , Gotoh Y. , Nagura M. , Endo R. , Hara T. 
Published: January 2004

AbstractFibers of PA9‐T, a new semiaromatic polyamide containing a long aliphatic chain, were prepared by melt spinning. As‐spun fibers were subsequently drawn with a CO2 laser‐heated drawing system at different draw ratios and various drawing velocities. On‐line observations of drawing points deciphered two drawing states; namely, flow drawing and neck drawing, over the entire range of drawing. Drawing stress revealed that flow drawing is induced by slight drawing stress under a low draw ratio up to 3, and neck drawing is induced by relatively high drawing stress under a higher draw ratio. The effect of drawing stress and drawing velocity on the development of the structure and properties has been characterized through analysis of birefringence, density, WAXD patterns, and tensile, thermal, and dynamic viscoelastic properties. For the neck‐drawn fibers, almost proportional enhancements of crystallinity and molecular orientation with drawing stress were observed. The flow‐drawn fibers have an essentially amorphous structure, and birefringence and density do not always have a linear relation with properties. The fibers drawn at high drawing speed exhibit improved fiber structure and superior mechanical properties. The maximum tensile strength and Young's modulus of PA9‐T drawn fibers were found to be 652 MPa and 5.3 GPa, respectively. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 433–444, 2004
Fiber property and structure development of polyester blend fibers reinforced with a thermotropic liquid‐crystal polymer
Authors: Kim Jun Young , Kim Seong Hun , Kikutani Takeshi 
Published: January 2004

AbstractTernary blend fibers (TBFs), based on melt blends of poly(ethylene 2,6‐naphthalate), poly(ethylene terephthalate), and a thermotropic liquid‐crystal polymer (TLCP), were prepared by a process of melt blending and spinning to achieve high‐performance fibers. The reinforcement effect of the polymer matrix by the TLCP component, the fibrillar structure with TLCP fibrils of high aspect ratios, and the development of more ordered and perfect crystalline structures by an annealing process resulted in the improvement of the tensile strength and modulus for the TBFs. An increase in the apparent crystallite size with the spinning speed was attributed to the development of larger crystallites and more ordered crystalline structures in the annealed TBFs. The birefringence and density of the TBFs increased with increasing spinning speed, the TBFs becoming more oriented and the crystal packing becoming more enhanced. The molecular orientation was an important factor in determining the tensile strength and modulus of the TBFs. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 395–403, 2004
Space charge distribution in bending‐electrostrictive polyurethane films doped with salts
Authors: Watanabe Masashi , Hirai Toshihiro 
Published: January 2004

AbstractPolyurethane films bent during a field application (1.5 MV/m). Doping the films with salts controlled the bending direction. With ZnBr2, Zn(ClO4)2, and Cu(ClO4)2 as the dopants, the films bent to the anode side. Contrarily, CH3COONa‐doped, NaBr‐doped, and undoped films bent to the cathode side. We also measured the space charge distribution in the films to clarify the factor that determined the direction. The measurements were carried out with a pulsed electroacoustic method. For the films that bent to the anode side, a positive space charge was observed inside the cathode during the field application. However, for the films that bent to the cathode side, there was a negative space charge inside the anode. Thus, the dopants also controlled the space charge distribution, which corresponded to the bending direction. These results suggested a causality between the field‐induced bend of the film and the space charge distribution. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 523–531, 2004
Plasticized microporous poly(vinylidene fluoride) separators for lithium‐ion batteries. II. Poly(vinylidene fluoride) dense membrane swelling behavior in a liquid electrolyte—characterization of the swelling kinetics
Authors: Saunier J. , Alloin F. , Sanchez J. Y. , Barrière B. 
Published: January 2004

AbstractSome microporous poly(vinylidene fluoride) (PVdF) separators for lithium‐ion batteries, used in liquid organic electrolytes based on a mixture of carbonate solvents and lithium salt LiPF6, were characterized by the study of the swelling phenomena on dense PVdF membranes. Various aspects of the kinetics of the carbonate solvents and the solvent mixture sorption in dense PVdF slabs were studied at different temperatures. Non‐Fickian behavior, characterized by S‐shaped sorption curves, was highlighted, and a salt effect, which resulted in two‐stage sorption, was studied. Diffusion coefficients and activation energies were calculated for the Fickian portions of the sorption curves, that is, at short times and low swelling ratios. A strong influence of the different interaction parameters was shown for the swelling kinetics. This study proved that the swelling of microporous PVdF membranes could be considered instantaneous. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 544–552, 2004
Plasticized microporous poly(vinylidene fluoride) separators for lithium‐ion batteries. I. Swelling behavior of dense membranes with respect to a liquid electrolyte—Characterization of the swelling equilibrium
Authors: Saunier J. , Alloin F. , Sanchez J. Y. , Barrière B. 
Published: January 2004

AbstractSome poly(vinylidene fluoride) (PVdF) microporous separators for lithium‐ion batteries, used in liquid organic electrolytes based on a mixture of carbonate solvents and lithium salt LiPF6, were characterized by the study of the swelling phenomena on dense PVdF membranes. We were interested in the evolution of the swelling ratios with respect to different parameters, such as the temperature, swelling solution composition, and salt concentration. To understand PVdF behavior in microporous membranes and, therefore, to have a means of predicting its behavior with different solvent mixtures, we correlated the swelling ratios in pure solvents and in solvent mixtures to the solvent–polymer interaction parameters and solvent–solvent interaction parameters. We attempted a parametric identification of swelling curves with a very simple Flory–Huggins model with relative success. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 532–543, 2004
Surface roughness in dynamically crystallized isotactic polypropylene films
Authors: González V. A. , Alanís M. , Guerrero C. , Ortiz U. 
Published: January 2004

AbstractThe relationship between the dynamic crystallization conditions and surface topography of iso‐polypropylene (i‐PP) films was examined with fractal geometry. When i‐PP was crystallized from a melt at cooling rates in the range between 1 and 100 °C/min, the generated surface topography presented self‐affine behavior at least in the scale range from 0.1 to 100 μm. Moreover, the calculated roughness exponent of these surfaces increased with the cooling rate used to crystallize the samples, which meant a smoother surface at higher crystallization rates. This behavior could be qualitatively explained in terms of the temperature effect on the nucleus stability, the molecular mobility, and the surface tension. In addition, the morphology of quenched samples was analyzed, and different hypotheses were proposed to explain the unusual observed behavior. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 646–655, 2004
Molecular orientation of a ZnS‐nanocrystal‐modified M13 virus on a silicon substrate
Authors: Ni Jingping , Lee Seung‐Wuk , White John M. , Belcher Angela M. 
Published: January 2004

AbstractThe surface structure and cast film formation process of a ZnS‐nanocrystal‐modified M13 bacteriophage (ZnS–M13) were investigated. A ZnS–M13 film oriented under the influence of a capillary force was obtained on both single‐crystal and polycrystalline substrates. The film formation process was investigated with atomic force microscopy and scanning electron microscopy. The surface images showed that the degree of orientation of the molecular long axes greatly depended on the direction of force and the concentration of aqueous solutions. Controlling the aqueous solution concentration yielded a highly oriented ZnS–M13 film on an indium tin oxide plate. The ability to control the orientation of virus‐based films may lead to new types of hybrid materials in which the components are organized on several length scales. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 629–635, 2004
Anomalous small‐angle X‐ray scattering characterization of composites based on sulfonated poly(ether ether ketone), zirconium phosphates, and zirconium oxide
Authors: Prado L. A. S. De A. , Wittich H. , Schulte K. , Goerigk G. , Garamus Vasil M. , Willumeit R. , Vetter S. , Ruffmann B. , Nunes S. P. 
Published: January 2004

AbstractThe morphology and distribution of zirconium oxide and zirconium phosphates in a matrix of sulfonated poly(ether ether ketone) (SPEEK) were investigated with anomalous small‐angle X‐ray scattering (ASAXS) and electron microscopy. ASAXS revealed that ZrO2 was distributed in the SPEEK matrix in the form of nanoparticles smaller than 13 Å. A decrease in the conductivity suggested that the sulfonic groups were bound to the zirconium oxo species at the particle surface. Furthermore, two kinds of membranes containing zirconium phosphate were investigated. In one case, the phosphate was directly dispersed in the polymer solution for the casting of the membrane. In the other case, the phosphate was previously treated with n‐propyl ammonium and polybenzimidazole. From ASAXS data, the fractal dimension could be estimated. Mass‐fractal behavior was confirmed for the SPEEK membrane containing previously exfoliated zirconium phosphate, with aggregates of 6.3–165 Å. Surface‐fractal behavior was detected for membranes with untreated phosphates, with aggregates of 6.4–185 Å. The untreated phosphates caused an increase in the permeability, without changing the proton conductivity much. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 567–575, 2004
Crystallization kinetics in shearing‐induced oriented and stretched poly(ethylene oxide)
Authors: Jiang Shichun , An Lijia , Jiang Bingzheng 
Published: January 2004

AbstractIsothermal crystallization kinetics in the melting of poly(ethylene oxide) (PEO) were investigated as a function of the shear rate and crystallization temperature by optical microscopy. The radial growth rates of the spherulites are described by a kinetics equation including shearing and relaxation combined effects and the free energy for the formation of a secondary crystal nucleus. The free‐energy difference between the liquid and crystalline phases increased slightly with rising shearing rates. The experimental findings showed that the influence of the relaxation of PEO, which is related to the shear‐induced orientation and stretch in a PEO melt, on the rate of crystallization predominated over the influence of the shearing. This indicated that the relaxation of PEO should be more important so that the growth rates increase with shearing, but it was nearly independent of the shear rate within the measured experimental range. © 2004 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 42: 656–665, 2004
Functional and anatomical effects of hormonally induced experimental prostate growth: A urodynamic model of benign prostatic hyperplasia (BPH) in the beagle
Authors: Yokota Takeshi , Honda K. , Tsuruya Y. , Nomiya M. , Yamaguchi Osamu , Gotanda K. , Constantinou Christos E. 
Published: January 2004

AbstractBACKGROUNDBenign prostatic hypertrophy (BPH) produces a variety of changes in the urodynamic pattern of micturition and is usually associated with high detrusor voiding pressure and poor urine flow‐rate. In most previous experimental models, designed to simulate this condition, some degree of obstruction is immediately imposed by the technique employed to produce urethral occlusion. Consequently these models cannot reproduce the gradual onset of obstruction. In the present study a canine prostatic enlargement model, using 5α‐dihydrotestosterone (DHT) + 17β‐estradiol (E) was adapted in order to produce a more gradual onset of partial obstruction and impaired voiding.MATERIALS AND METHODSHormonally induced prostatic enlargement was produced using seven beagles, given DHT 75 mg/day together with E 0.75 mg/day for 28 days via an implantable pump. The functional effects of DHT + E treatment on micturition pressure/flow were measured in the conscious animal. Identical measurements were also made using a separate older group of five beagles with symptoms of BPH. In addition seven beagles similarly instrumented were used as controls.RESULTSPressure/flow studies show that DHT + E produced obstructive micturition, characterized by a significantly increased micturition detrusor pressure, from 33.3 ± 10.5 to 50.8 ± 10.7 cmH2O and significantly decreased low urine flow‐rate from 8.6 ± 2.1 to 6.9 ± 0.9 ml/sec. Associated with the obstructive micturition, this treatment increased wet prostate weight from 11.9 ± 2.5 to 31.6 ± 10.0 g. Prostate volume of the BPH beagles was 29.3 ± 8.9 g. Morphologic studies show that DHT + E produced epithelial hyperplasia extending focally into the lumen.CONCLUSIONSHormonally induced prostate growth produced bladder obstruction, in terms of pressure/flow characteristics, that are analogous to BPH. It is suggested that this type of hormonal treatment can be used to create a model for the study of the effects of controlled increased in prostate growth and the development of BPH on micturition. © 2003 Wiley‐Liss, Inc.