bluuebunny/crossref_metadata_2025_split huggingface dataset:
Miscibility behavior and coil overlap in ionic blends of phenylated polytriphenylene oxide and poly(methyl methacrylate)
Authors: Rajagopalan M. , Natansohn A. , Eisenberg A. , Tannenbaum R. 
Published: May 2003

AbstractBlends of sulfonated phenylated polytriphenylene oxide and poly(methyl methacrylate‐co‐4‐vinyl pyridine) were examined by dynamic mechanical, Fourier transform infrared, and NMR techniques. A high degree of miscibility was evident from a single drop in a plot of the storage modulus versus the temperature. The presence of ionic moieties due to proton transfer from sulfonic acid to 4‐vinyl pyridine was confirmed by both NMR and IR spectroscopy studies. The coils were found to be close to one another in dimethyl sulfoxide‐d6 because the aromatic shielding effect of the phenyl rings of the phenylated polytriphenylene oxide units was observed from the upfield shift of most of the protons of poly(methyl methacrylate) in the NMR spectrum. However, the absence of cross peaks in the nuclear Overhauser and exchange spectroscopy experiments suggested that the intermolecular distance between the chains had to be larger than 4 Å. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 728–733, 2003
Structural insights into a novel molecular‐scale composite of soluble poly(vinyl pyrrolidone) supporting uniformly dispersed nanoscale poly(vinyl pyrrolidone) particles
Authors: Hood David K. , Senak Laurence , Kopolow Steven L. , Tallon Michael A. , Kwak Yoon Tae , Patel Drupesh , McKittrick John 
Published: May 2003

AbstractStructural insights into a novel, molecular‐composite poly(vinyl pyrrolidone) consisting of a soluble, film‐forming poly(vinyl pyrrolidone) (PVP) polymer and in situ formed, minute, crosslinked, nanoscale, insoluble poly [poly(vinyl pyrrolidone)] (PPVP) polymer particles are reported. A technique for determining the PVP molecular weight and PPVP weight fraction by gel permeation chromatography/multi‐angle light scattering (MALS) is described. Particle size studies by quasi‐elastic light scattering and field flow fractionation/MALS demonstrate that the nanoscale, insoluble polymer particles are nominally 370 and 325 nm in diameter, respectively. Rheological experiments on this dispersed system yield a complex macroscopic behavior. Atomic force microscopy images confirm a substantial heterogeneous nature for a film cast from this molecular‐composite material. Finally, this polymeric molecular composite in film form exhibits, among many other interesting properties, a dramatic enhancement in water resistance, as demonstrated by a simple image water resistance test for an ink‐jet printing application. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 734–741, 2003
Mechanochemical improvement of the flame‐retardant and mechanical properties of zinc borate and zinc borate–aluminum trihydrate‐filled poly(vinyl chloride)
Authors: Pi Hong , Guo Shaoyun , Ning Yong 
Published: May 2003

AbstractIn this study, the effect of the high‐energy mechanical milling of a mixture of poly(vinyl chloride) (PVC) with zinc borate (ZB) or ZB–aluminum trihydrate (ATH), a mixture of ZB and ATH, on the flame‐retardant and mechanical properties of ZB and ZB–ATH filled PVC was examined. The high‐energy mechanical milling of PVC/ZB and the PVC/ZB–ATH mixture produced chemical bonding between PVC and ZB or ZB–ATH, increasing the interfacial interaction of PVC/ZB and PVC/ZB–ATH blends, which resulted in a great increase in the limiting oxygen index, the impact and yield strengths, and the elongation at break of PVC/ZB and PVC/ZB–ATH blends. The results from ultraviolet spectroscopy and gas chromatography–mass spectroscopy show that mechanochemical modification of ZB and ZB–ATH much more effectively suppressed the release of aromatic compounds in PVC/ZB and PVC/ZB–ATH blends during burning. Mechanochemical modification provided an excellent route for the improvement of the flame‐retardant and mechanical properties of flame‐retardant‐additive‐filled PVC. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 753–762, 2003
Production of polystyrene/poly(ethylene glycol dimethacrylate) composite particles encapsulating hinokitiol
Authors: Okubo M. , Minami H. , Jing Y. 
Published: May 2003

AbstractPolystyrene (PS)/poly(ethylene glycol dimethacrylate) composite polymer particles containing hinokitiol (HT) were produced by suspension polymerization for ethylene glycol dimethacrylate droplets by the dissolution of HT and PS in poly(vinyl alcohol) aqueous solution. The composite particle had a hollow structure in which HT was included. The evaporation rate of HT from the composite particles became slower than that of pure HT. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 706–710, 2003
Modifying tubule distribution in tubule‐filled composites by using polyurethane–polydimethylsiloxane interpenetrating polymer networks
Authors: Chiou Bor‐Sen , Lankford Andrew R. , Schoen Paul E. 
Published: May 2003

AbstractMicrotubules that were made from a phospholipid and coated with copper to become electrically conductive were incorporated into a polyurethane–polydimethylsiloxane (PU‐PDMS) interpenetrating polymer network. The tubule concentration ranged from 8 to 16 vol %, whereas the PDMS concentration ranged from 0 to 75 wt %. The composites' dielectric properties and morphology were characterized by using a vector network analyzer and an optical microscope. In the composites the tubules became segregated into the polyurethane phase and were excluded from the PDMS phase. This forced the tubules closer together and resulted in the sample being closer to percolation. Consequently, for a specific tubule concentration, the real part of the permittivity increased for higher PDMS concentrations. In addition, adding tubules changed the morphology of the matrix. The dispersed PDMS globules were smaller in the composites than in the neat interpenetrating polymer network. The reason was that the tubules increased the viscosity of the system, which prevented the smaller PDMS globules from coalescing to form larger globules. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1032–1038, 2003
Isothermal crystallization of poly(vinyl alcohol–co–ethylene)
Authors: Alvarez Vera A. , Kenny José M. , Vázquez Analía 
Published: May 2003

AbstractIsothermal melt crystallization of poly(vinyl alcohol–co–ethylene) with different ethylene contents was studied in the temperature range of 140°C–160°C. A differential scanning calorimeter was used to follow the energy of the crystallization process. The results were analyzed by Avrami and Hoffman–Laurizten methods. The Avrami exponent was close to 2, indicating two‐dimensional growth with a linear growth rate and crystals nucleating athermally. The equilibrium melting temperature was determined by the Hoffman–Weeks method. The rate of crystallization depended on ethylene content and temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1071–1077, 2003
A novel wood‐binding domain of a wood–plastic coupling agent: Development and characterization
Authors: Zhang C. , Li K. , Simonsen J. 
Published: May 2003

AbstractPoly(N‐acryloyl dopamine) (PAD) was successfully synthesized through free‐radical homopolymerization of N‐acryloyl‐O,O′‐diphenylmethyldopamine and subsequent deprotection. The adhesive ability of PAD to wood was studied in detail. PAD underwent substantial oxidation and crosslinking reactions at about 80°C. Therefore, maple veneer samples bonded with PAD powder at a press temperature of 120°C had high shear strength and high water resistance. In contrast to conventional wood adhesives such as phenol‐formaldehyde and urea‐formaldehyde resins, PAD resulted in an increase, rather than a decrease, in the shear strengths of two‐ply laminated maple veneer test specimens that had undergone a water soaking and drying treatment. A mixture of PAD and polyethylenimine (PEI) resulted in much higher shear strength than PAD alone. To achieve high shear strength and high water resistance, the maple specimens bonded with PAD–PEI mixtures had to be cured above 150°C because reactions between PAD and PEI occurred at about 150°C. The water resistance of the maple specimens bonded with the PAD–PEI mixtures was dependent on the PAD:PEI weight ratio and the curing temperature. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1078–1084, 2003
Toughening of polyethylene terephthalate/amorphous copolyester blends with a maleated thermoplastic elastomer
Authors: Yu Zhong‐Zhen , Lei Ming , Ou Yuchun , Yang Guisheng 
Published: May 2003

AbstractThe toughening of polyethylene terephthalate (PET)/amorphous copolyester (PETG) blends using a maleic anhydride grafted mixture (TPEg) of polyethylene‐octene elastomer and a semicrystalline polyolefin plastic (60/40 by weight) was examined. The TPEg was more effective in toughening PETG than PET, although the dispersion qualities of the TPEg particles in PET and PETG matrices were very similar. At the fixed TPEg content of 15 wt %, replacing partial PET by PETG resulted in a sharp brittle‐ductile transition when the PETG content exceeded the PET content. Before the transition, PET/PETG blends were not toughened with the TPEg of 15 wt %, whereas after the transition, the PET/PETG blends with 15 wt % of TPEg, similar to the PETG/TPEg (85/15) binary blend, maintained a super‐tough level. The impact‐fractured surfaces of the PET/PETG/TPEg blends were also evaluated. When PETG content was lower than PET content, the ternary blend showed a brittle feature in its impact‐fractured surface, similar to the PET/TPEg (85/15) binary blend. While PETG content exceeded PET content, however, the impact‐fractured surface of the ternary blend was very similar to that of PETG/TPEg (85/15) binary blend, exhibiting intensive cavitation and massive matrix shear yielding, which were believed to be responsible for the super‐tough level of the blends. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 797–805, 2003
Synthesis and characterization of σ–π conjugated poly(methylphenyldiethynylenesilane‐co‐methyltetraphenylphenylsilylene)
Authors: Li Meijiang , Feng Shengyu , Xie Shijie 
Published: May 2003

AbstractDiacetylenemethylphenylsilane (1) and dichloromethyltetraphenylphenylsilane (2) were synthesized by the reactions of ethynylmagnesium bromide with dichloromethylphenylsilane and dichloromethylvinylsilane with tetraphenylcyclopentadienone, respectively. The copolymers of 1 and 2 were obtained by sodium condensation reaction. They were characterized by FTIR,1H‐ and 13C‐NMR, and both UV and fluorescence spectroscopy. The molecular weights of polymers were determined by GPC relative to polystyrene standards. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 806–810, 2003
Rheological properties and compatibility of NR/EPDM and NR/brominated EPDM blends
Authors: Lewis Chonlada , Bunyung Sunsanee , Kiatkamjornwong Suda 
Published: May 2003

AbstractEthylene–propylene–diene terpolymer (EPDM) was modified by bromination reaction. Blending the resulting brominated EPDM with natural rubber (STR5L) and blending the unmodified EPDM with STR5L at various compositions were carried out. The rheological properties of the blends were investigated using a capillary extrusion. Shear flow curves of the pure rubbers and their blends illustrated the pseudoplastic property as shear thinning behavior with a power law index n < 1. True shear viscosity of all blends showed the negative deviation in relation to their additive values. Rheological behavior and two Tg's found from the DSC thermograms at all blend compositions indicated blend incompatibility for both sets of blends. The incompatibility of the vulcanized blends was also found by measuring the spin–spin relaxation time T2 by pulsed NMR. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 837–847, 2003
Effects of fillers, maleated ethylene propylene diene diene rubber, and maleated ethylene octene copolymer on phase morphology and oil resistance in natural rubber/nitrile rubber blends
Authors: Sirisinha Chakrit , Limcharoen Sauvarop , Thunyarittikorn Jarunee 
Published: May 2003

AbstractThe phase morphology and oil resistance of 20/80 NR/NBR blends filled with different types of fillers and copolymers were investigated. In the case of filler effect, N220, N330, and N660 carbon blacks with different particle sizes were used. Additionally, the blends filled with nonblack‐reinforcing fillers, that is, precipitated and silane‐treated silica, were investigated. To study the compatibilization effect, maleated ethylene propylene diene rubber (EPDM‐g‐MA) and maleated ethylene octene copolymer (EOR‐g‐MA) were added to the blends. The results revealed that the addition of filler, either carbon black or silica, to the blend caused a drastic decrease in NR dispersed phase size. Carbon blacks with different particle sizes did not produce any significant difference in NR dispersed phase size under the optical microscope. Silica‐filled blends showed lower resistance to oil than did the carbon black–filled blends. In addition, it was determined that neither EOR‐g‐MA nor EPDM‐g‐MA could act as a compatibilizer for the blend system studied. The oil resistance of the blends with EPDM‐g‐MA is strongly affected by the overall polarity of the blend. In the case of EOR‐g‐MA, the oil resistance of the blends is significantly governed by both overall polarity of the blend and phase morphology. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 1156–1162, 2003
Functional anatomy and hemodynamic characteristics of vasa vasorum in the walls of porcine coronary arteries
Authors: Gössl Mario , Rosol Michael , Malyar Nasser M. , Fitzpatrick Lorraine A. , Beighley Patricia E. , Zamir Mair , Ritman Erik L. 
Published: May 2003

AbstractIn this study vasa vasorum in the walls of porcine coronary arteries were examined, using three‐dimensional (3D) micro‐CT scanning techniques. These techniques leave the 3D structure of the vasa vasorum tree intact and thus provide a much more direct view of this structure than is possible from conventional histological sections. The study demonstrates—for the first time, we believe—both the different types and the fine architecture of these vasa vasorum. Furthermore, with the use of automated tree analysis software, it was possible to obtain quantitative geometrical data on the 3D structure of vasa vasorum trees that have not previously been available. The results indicate that despite the restrictive topology of the space in which they are present, the branching architecture of the vasa vasorum trees, which we surveyed, is surprisingly similar to that of vasculature in general. The volume of vessel wall tissue perfused or drained by a vasa vasorum tree was found to correlate well with the cross‐sectional area of the root segment of the vasa vasorum tree, and the luminal surface area corresponding to this volume was found to be comparable with the surface area of an early atherosclerotic lesion. This is consistent with earlier findings that the ligation or removal of vasa vasorum leads to atherogenesis. Anat Rec Part A 272A:526–537, 2003. Published 2003 Wiley‐Liss, Inc.
Neurocan in the embryonic avian heart and vasculature
Authors: Mishima Noboru , Hoffman Stanley 
Published: May 2003

AbstractThe chondroitin sulfate proteoglycan (CSPG) neurocan was previously considered to be nervous‐system specific. However, we have found neurocan in the embryonic heart and vasculature. In stage 11 quail embryos, neurocan was prominently expressed in the myocardium, dorsal mesocardium, heart‐forming fields, splanchnic mesoderm, and vicinity of the extraembryonic vaculature, and at lower levels in the endocardium. A comparison of neurocan staining with QH1 staining of vascular endothelial cells demonstrates that neurocan is frequently expressed by cells adjacent to endothelial cells, rather than by endothelial cells themselves. In some cases, a dispersed subset of cells are neurocan‐positive in a field of cells that otherwise appear uniform in morphology. Later in development, neurocan expression becomes relatively limited to the nervous system. However, even in 10‐day embryos, neurocan is expressed in the chorio‐allantoic membrane in the tissue that separates closely packed, small‐diameter blood vessels. In summary, our results suggest that neurocan may function as a barrier that regulates vascular patterning during development. Anat Rec Part A 272A: 556–562, 2003. © 2003 Wiley‐Liss, Inc.
Renal corpuscle of the sturgeon kidney: An ultrastructural, chemical dissection, and lectin‐binding study
Authors: Ojeda José L. , Icardo José M. , Domezain Alberto 
Published: May 2003

AbstractThe sturgeon is an ancient species of fish that thrives in a wide range of ecological environments, from freshwater to seawater. Basic in this process of adaptation is the ability of the kidney to control fluid filtration and urine formation. However, the morphological basis of this process is mostly unknown. The aim of the present study was to use microdissection techniques (scanning electron microscopy (SEM), transmission electron microscopy (TEM), and lectin‐binding histochemistry) to examine the structure of the renal corpuscle of the sturgeon Acipenser nacarii in order to reveal morphologic features that could be related to function, phylogeny, and habitat. The renal corpuscles are aligned along the intrarrenal arteries. The urinary pole shows a siphon‐like neck segment (NS) in 92% of the nephrons, whose structural characteristics are different from those of other fish. The podocytes have cuboidal cellular bodies, intercellular contacts, and poorly developed cell processes. The podocyte glycocalyx contains N‐acetylglucosamine and lacks sialic acid. The structural and lectin‐binding patterns are similar to those found in the immature mammalian kidney. The glomerular basement membrane (GBM) is very thick and consists of three layers: a lamina rara externa, a lamina densa, and a thick subendothelial lamina. The latter contains tubular microfibrils, collagen fibers, and long mesangial cell processes. Frequently, the podocyte bodies attach directly to the GBM, and the area occupied by the filtration slits is very small. Furthermore, the GBM shows a glycosylation pattern different from that observed in most vertebrates. Contrary to what would be expected in sturgeons living in freshwater, the A. nacarii renal corpuscle morphology suggests a low glomerular filtration rate. Anat Rec Part A 272A: 563–573, 2003. © 2003 Wiley‐Liss, Inc.
On some measures and distances for positive random variables
Authors: Finkelstein M. S. 
Published: May 2003

AbstractA number of conventional measures of risk as real‐valued functions on the space of positive random variables are considered: the expected shortfall, the mean excess over the threshold, the stop‐loss and some others. Ordering of risks, based on these measures and the distances between corresponding distribution functions, are described. The perturbed measures, describing the effect of changing environment, are discussed. These measures are defined by the accelerated life and proportional hazards models widely used in reliability and survival analysis. The case of a random environment is of a prime interest in the paper. The main result states that if, for instance, the stochastic environment is ‘neutral in expectation’ with respect to the baseline one, the distance between the corresponding distribution functions can be still sufficiently large. Copyright © 2003 John Wiley & Sons, Ltd.
Release kinetics of transforming growth factor‐β1 from fibrin clots
Authors: Giannoni Paolo , Hunziker Ernst B. 
Published: May 2003

AbstractIn any therapeutic model involving a tissue‐engineering approach to the repair of partial‐thickness articular cartilage defects, a chondrogenic differentiation factor is required to ensure tissue‐specific healing. Transforming growth factor‐β1 (TGF‐β1) is known to act in this capacity, but at such high concentrations as to render its direct injection into the joint cavity inadvisable. This situation calls for a delivery system that can be applied directly to the defect site and that will release the drug gradually over a period of some weeks. Liposome encapsulation represents one such system, and has been recently implemented with some success in an animal model for cartilage repair. However, the kinetics of TGF‐β1 release have not been determined, it was the purpose of the present study to characterize these. The liberation of [125I]‐labeled TGF‐β1 from fibrin matrices containing this agent in either a free or liposome‐encapsulated form was monitored by liquid scintillation counting for 25 days in vitro. During the initial 5 days, fibrin clots containing liposome‐encapsulated TGF‐β1 released this cytokine at a slower rate (2% to 4% per day) than did those containing the free molecules (10% to 20% per day); thereafter, the release rates were similar. At the end of the incubation period, only 40% of the liposome‐encapsulated TGF‐β1 had been released from the fibrin clots, as compared with 68% from those containing the free molecules. Liposome encapsulation thus represents a suitable means of establishing a slow‐delivery system in tissue‐engineering approaches to articular cartilage repair. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 121–123, 2003.
Macrokinetic and quantitative microbial investigation on a bench‐scale biofilter treating styrene‐polluted gaseous streams
Authors: Zilli Mario , Converti Attilio , Di Felice Renzo 
Published: May 2003

AbstractWe performed a macrokinetic and quantitative microbial investigation of a continuously operating bench‐scale biofilter treating styrene‐polluted gases. The device was filled with a mixture of peat and glass beads as packing medium and inoculated with the styrene‐oxidizing strain, Rhodococcus rhodochrous AL NCIMB 13259. The experimental data of styrene and microbial concentrations, obtained at different biofilter heights, were used to evaluate the pollutant concentration profiles as well as the influence of styrene loading on biomass distribution along the packing medium. Styrene and biomass concentration profiles permitted detection of a linear relationship between the amount of biomass grown in a given section of the biofilter and that of pollutant removed, regardless of the operating conditions tested. Biomass development in the bed appeared to: depend linearly on pollutant concentration at an inlet styrene concentration of <0.10 g m−3 in the gaseous stream; achieve a maximum value (7 · 107 colony forming units per gram of packing material) within a wide styrene concentration range (0.10 to 1.0 g m−3); and fall sharply beyond this inhibition threshold. The process followed zeroth‐order macrokinetics with respect to styrene concentration, which is consistent with zeroth‐order microkinetics with either fully active or not fully active biofilm. The maximal volumetric styrene removal rate was found to be 63 g mpacking material−3 h−1 for an influent pollutant concentration of 0.80 g m−3 and a superficial gas velocity of 245 m h−1. © 2003 Wiley Periodicals, Inc. Biotechnol Bioeng 83: 29–38, 2003.