bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and characterization of Pst‐b‐PDMS‐b‐PSt copolymers by atom transfer radical polymerization
Authors: Peng Hui , Cheng Shiyuan , Fan Zhiqiang 
Published: April 2004

AbstractPolystyrene‐b‐poly(dimethylsiloxane)‐b‐polystyrene (Pst‐b‐PDMS‐b‐PSt) triblock copolymers were synthesized by atom transfer radical polymerization (ATRP). Commercially available difunctional PDMS containing vinylsilyl terminal species was reacted with hydrogen bromide, resulting in the PDMS macroinitiators for the ATRP of styrene (St). The latter procedure was carried out at 130°C in a phenyl ether solution with CuCl and 4, 4′‐di (5‐nonyl)‐2,2′‐bipyridine (dNbpy) as the catalyzing system. By using this technique, triblock copolymers consisting of a PDMS center block and polystyrene terminal blocks were synthesized. The polymerization was controllable; ATRP of St from those macroinitiators showed linear increases in Mn with conversion. The block copolymers were characterized with IR and 1H‐NMR. The effects of molecular weight of macroinitiators, macroinitiator concentration, catalyst concentration, and temperature on the polymerization were also investigated. Thermodynamic data and activation parameters for the ATRP are reported. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3764–3770, 2004
The effect of maleic anhydride modified polypropylene on the mechanical properties of feather fiber, kraft pulp, polypropylene composites
Authors: Bullions T. A. , Gillespie R. A. , Price‐O'Brien J. , Loos A. C. 
Published: April 2004

AbstractComposites made of feather fiber (Ff), kraft pulp fiber (Pf), polypropylene (PP), and maleic anhydride modified polypropylene (MaPP) were tested in tension and three‐point bend tests. Composite panels were compression molded from multiple plies of nonwoven, fabric‐like prepreg manufactured with wetlay papermaking equipment. Composites containing all four materials were manufactured with MaPP substitutions for PP of 0–10 wt % at 2 wt % increments. The best mechanical properties were observed with a substitution of 8 wt % MaPP. Composites containing either Pf or Ff were manufactured with MaPP substitutions for PP of 0, 4, and 8 wt %; mechanical properties improved with increases in MaPP content. The improvements in mechanical properties were attributed to fiber/matrix interface improvement by the addition of MaPP. Scanning electron microscopy revealed evidence of improved interfacial bonding on the tensile fracture surfaces. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3771–3783, 2004
Aspects of the crosslinking of polyethylene with vinyl silane
Authors: Shah Gul Bali , Fuzail Mohammad , Anwar Jamil 
Published: April 2004

AbstractThe crosslinking reaction of low‐density polyethylene with vinyl triethoxysilane was studied in great detail. The effects of a wide range of concentrations (0–27.33 phr silane and 0–1.25 phr benzoyl peroxide) on the mechanical properties, hot‐set testing, gel contents, and burning behaviors of the resulting crosslinked polyethylene were studied. The effect of variations in the concentration of silane was found to be a dictating parameter for all these properties. Moreover, at or above a certain threshold concentration of silane (4.56 phr), samples not only qualified for hot‐set testing but also showed other properties at an optimum level. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3796–3803, 2004
Use of acrylate‐based liquid rubbers as toughening agents and adhesive property modifiers of epoxy resin
Authors: Kar Sritama , Banthia Ajit K. 
Published: April 2004

AbstractCarboxyl‐randomized poly(2‐ethyl hexyl acrylate) (CRPEHA) and epoxy‐randomized poly(2‐ethylhexyl acrylate) (ERPEHA) were synthesized by solution polymerization technique in the form of liquid rubbers. The liquid rubbers were characterized by IR and 1H‐NMR spectroscopic analysis, nonaqueous titration, and GPC. The liquid rubbers were pre‐reacted with the epoxy resin and the modified epoxy networks were made by curing with an ambient temperature curing agent. The modified epoxy networks containing different concentrations of CRPEHA (A‐1) and ERPEHA (B‐1) were evaluated with respect to their thermal and impact properties. The optimum properties were obtained at 10‐phr concentration of a (1 : 1) mixture of CRPEHA and ERPEHA. Fracture surface analysis by scanning electron microcopy indicated the presence of a two‐phase microstructure. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3814–3821, 2004
Curing behavior of epoxy resin/tung oil anhydride exfoliated nanocomposite by differential scanning calorimetry
Authors: Bao Suping , Shen Shijun , Liang Guodong , Zhai Hongbo , Xu Weibing , He Pingsheng 
Published: April 2004

AbstractThe nanocomposite of epoxy resin/tung oil anhydride/organic montmorillonite was prepared by casting and curing. The distance of the clay gallery rose and the exfoliated nanocomposite was formed. The exfoliation behaviors of the nanocomposite had been investigated by X‐ray diffraction (XRD). The curing mechanism and kinetics of epoxy resin with the different amounts of organic montmorillonite were studied using isothermal and dynamic methods by differential scanning calorimetry (DSC). Some parameters, the activation energy and reaction orders, were calculated by the modified Avrami equation in analysis of the isothermal experiment. The total curing mechanism and kinetics of curing reaction were also analyzed by the Flynn–Wall–Ozawa method. It was noted that the instantaneous activity energy during the curing process could be obtained by the Flynn–Wall–Ozawa method and the trend of the results was in agreement with those obtained from the modified Avrami equation. These results show that the activity energy decreases with the addition of organic montmorillonite. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3822–3829, 2004
Study on morphology behavior of PVDF‐based electrolytes
Authors: Tian Li‐ying , Huang Xiao‐bin , Tang Xiao‐zhen 
Published: April 2004

AbstractThree nonelectrolyte samples and one gel polymer electrolyte sample were prepared from poly(vinylidene fluoride) (PVDF), propylene glycol carbonate (PC), and LiClO4 in the present article. Fourier transform infrared spectroscopy, dynamic mechanical analysis, differential scanning calorimetry, thermogravimetric analysis, X‐ray diffraction, and scanning electron microscopy were used to study morphology structure of all the samples. Results showed that there were great interactions among PVDF, PC, and lithium salt, which led to different morphology properties of different samples. Interactions between PVDF and PC mainly occurred on the surface area of PVDF crystalline, while interactions between PC, PVDF, and lithium salt mainly occurred in the amorphous area. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3839–3842, 2004
Metallization of crosslinked acrylate resin by reduction of polymer‐incorporated metal ion
Authors: Shibata Mitsuhiro , Abe Takahiro , Uda Takayasu 
Published: April 2004

AbstractCrosslinked acrylate resin were prepared by the radical polymerization of poly(ethylene glycol) diacrylate (ADE400) with 2,2′‐azobisisobutyronitrile in the presence of cobalt (II) chloride at 100°C for 48 h. Metallization behavior of the CoCl2‐containing acrylate resin by reduction with aqueous sodium tetrahydroborate solution at 25°C was investigated by means of infrared spectroscopy, X‐ray photoelectron spectroscopy, scanning electron microscopy, and electron probe microanalysis. As a result, the surface of the crosslinked acrylate resin was successfully metallized by the reduction, and the cobalt layer generated at the side of a polypropylene plate used in the preparation of film was thicker and smoother than the air side. Most of the chlorine ion in the film passed in the reduction solution. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3864–3868, 2004
Synthesis of fluoroalkyl end‐capped preoligomers containing succinimidyl segments—Application to novel fluorinated oligomers possessing surface antibacterial activity
Authors: Sawada Hideo , Yanagida Kenta , Kawase Tokuzo , Inaba Yoshiko , Sasazawa Kazuo , Sugiya Masashi 
Published: April 2004

AbstractFluoroalkyl end‐capped N‐acryloxysuccinimide (ASuI) cooligomers were prepared under very mild conditions by the cooligomerizations of fluoroalkanoyl peroxides with ASuI and comonomers such as N,N‐dimethylacrylamide (DMAA) and acryloylmorpholine (ACMO). These fluorinated ASuI cooligomers thus obtained were in general easily soluble in water and common organic solvents. These fluorinated ASuI cooligomers were also able to reduce the surface tension of water quite effectively to around 20 mN/m with a clear break point resembling a critical micelle concentration (CMC), although the corresponding nonfluorinated ASuI cooligomers were not effective for reducing the surface tension of water. Fluorinated ASuI cooligomers were applicable to new fluorinated precooligomers, and these precooligomers could react with several amino compounds such as aniline, cytosine, and cyclohexylamine to afford fluorinated cooligomer‐bound aromatic and cyclohexyl segments under mild conditions. Of particular interest, these fluorinated precooligomers were able to react with low molecular weight biocides such as sulfathiazole (STZ) and 3‐amino‐5‐hydroxypyrazole (AHP) to give the corresponding fluorinated cooligomers containing antibacterial segments under similar conditions. These cooligomers were shown to have not only a good oleophobicity imparted by fluorine but also surface antibacterial activity against Staphylococcus aureus. Therefore, our present fluorinated cooligomers containing antibacterial segments are suggested to have high potential for new fluorinated functional materials through their surface active property and surface antibacterial activity. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3874–3880, 2004
Physical properties and reaction kinetics of cotton cellulose crosslinked with dimethyloldihydroxyethyleneurea–maleic acid
Authors: Hsiung Han‐Hsing , Huang Hung‐Yu , Wang Yuen‐Hua , Wang Chang , Chen Jui‐Chin , Chen Cheng‐Chi 
Published: April 2004

AbstractTwo dicarboxylic acids were used to join with dimethyloldihydroxyethyleneurea (DMDHEU) as crosslinking agents to treated cotton fabrics. These results reveal that the dry crease recovery angle values of the treated fabrics for DMDHEU–maleic acid are higher than those for DMDHEU–tartaric acid at a given wet crease recovery angle and tensile strength retention. The IR spectra show that the reaction between the –OH of DMDHEU and cellulose and the vinyl groups of maleic acids occurred. The cross section of the DMDHEU–maleic acid and DMDHEU–tartaric acid treated fibers and the energies of activation and other data of reaction kinetics for DMDHEU–maleic acid and DMDHEU–tartaric acid strongly suggest that the reaction of vinyl groups of maleic acid with cellulose molecules can take place during the pad/dry‐cure process. Additionally, the surface distribution of crosslinking agent on the finished fabrics for DMDHEU–maleic acid is slightly lower than that for DMDHEU–tartaric acid. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3886–3893, 2004
Effects of a mixture of stabilizers on the structure and mechanical properties of polyethylene during reprocessing
Authors: Abad M. J. , Ares A. , Barral L. , Cano J. , Díez F. J. , García‐Garabal S. , López J. , Ramírez C. 
Published: April 2004

AbstractThe properties of two polyethylenes [a high‐density polyethylene (HDPE) and a low‐density polyethylene (LDPE)] were studied after several extrusion cycles. To reduce the degradation effects during the reprocessing, a mixture of two stabilizers was added to the formulations. The predominant degradation mechanism was chain scission for the HDPE and chain branching and crosslinking for the LDPE. For both polyethylenes the FTIR spectra exhibited a growth in the number of carbonyl groups as a function of the number of extrusion cycles. Their tensile properties were degraded with the reprocessing but both polyethylenes maintained their nearly constant thermal behavior and crystallinity. The addition of a primary phenolic antioxidant and a secondary phosphite antioxidant preserved the melt behavior of virgin materials after the reprocessing and reduced the degradation effects. From the tensile tests, the efficiency of the antioxidants in the LDPE was very high and, after the reprocessing, the material retained the mechanical properties of virgin LDPE. The efficiency of the antioxidants for the HDPE was not significant. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3910–3916, 2004
Synthesis and characterization of a cation‐exchange resin based on vinylpyrrolidone‐co‐divinylbenzene: Effect of nature and amount of diluent on different resin properties
Authors: Zaidi Syed Arif Raza , Ali Syed Wasim , Shah Gul Bali 
Published: April 2004

AbstractFundamental studies regarding the synthesis of a porous copolymer synthesized from 1‐vinyl‐2‐pyrrolidone and divinylbenzene in the presence of different diluents were carried out. A series of porous copolymer resins was synthesized by suspension polymerization using the following diluents: dimethylphthalate (DMT), diethylphthalate, dibutylphthalate, and bis‐2‐ethyl hexylphthalate [dioctylphthalate (DOT)]. It was observed that the porosity of resin increases with increase in length of the methylene group in the phthalate ester of DMT to DOT. In another series of experiments the amount of solvent was increased from 30 to 60% while the crosslinkage was kept constant at 30% and the diluent used was DOT. It was observed that the porosity of resins increased as the fraction of solvent increased. However, surprisingly, the Na+ capacity did not show any appreciable change by varying the amount or nature of diluent, remaining approximately 4 meq/g. The resin remained mechanically strong despite higher porosity. The mechanical strength also did not show any significant change by varying the diluent or amount of diluent. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3917–3920, 2004
Ultraviolet‐curing behavior and mechanical properties of a polyester acrylate resin
Authors: Kim Dae Su , Seo Woo Hyun 
Published: April 2004

AbstractUltraviolet (UV) curing technology has been widely used in many applications because it has several distinct advantages compared to solvent‐based processes or thermal‐curing technology. The effects of photoinitiator types and their contents as well as reactive diluent types and their contents on the UV‐curing behavior and mechanical properties of a UV‐curable polyester acrylate resin were investigated in this study. Three photoinitiators, Irgacure 184, Darocur 1173, and benzophenone, were used in this study. Hexanediol diacrylate, tripropylene glycol diacrylate, and trimethylol propane triacrylate were used as reactive diluents to modify the properties of the acrylate resin. The change of chemical structure during UV curing was monitored by FTIR. A universal testing machine was used to measure the tensile properties of various UV‐cured acrylate films of different compositions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 92: 3921–3928, 2004
Chondrogenesis of human bone marrow‐derived mesenchymal stem cells in agarose culture
Authors: Charles Huang C.‐Y. , Reuben Paul M. , D'Ippolito Gianluca , Schiller Paul C. , Cheung Herman S. 
Published: April 2004

AbstractMesenchymal stem cells derived from human bone marrow (hBM‐MSCs) can differentiate into chondrogenic cells for the potential treatment of injured articular cartilage. To evaluate agarose gels as a supportive material for chondrogenesis of hBM‐MSCs, this study examined chondrogenesis of hBM‐MSCs in the agarose cultures. Pellet cultures were employed to confirm the chondrogenic potential of the hBM‐MSCs that were used in agarose cultures. The hBM‐MSCs were seeded in 2% agarose constructs at the initial cell‐seeding densities of 3, 6, and 9 × 106 cells/ml while each of pellets was formed using 2.5 × 105 cells. Chondrogenesis of hBM‐MSCs was induced by culturing cell‐agarose constructs and pellets for 21 days in the presence of a defined medium containing transforming growth factor β3 (TGF‐β3). The analysis of reverse transcription‐polymerase chain reaction showed that hBM‐MSCs of agarose and pellet cultures expressed the chondrogenic markers of collagen type II and aggrecan in the presence of TGF‐β3. The deposition of cartilage‐specific macromolecules was detected in both agarose and pellet cultures by histological and immunohistochemical assessments. Chondrogenesis of hBM‐MSCs in agarose gels directly correlated with the initial cell‐seeding density, with the cell‐agarose constructs of higher initial cell‐seeding density exhibiting more cartilage‐specific gene expressions. This study establishes a basic model for future studies on chondrogenesis of hBM‐MSCs using the agarose cultures. Anat Rec Part A 278A:428–436, 2004. © 2004 Wiley‐Liss, Inc.
Development of the microcirculation of the secondary ossification center in rat humeral head
Authors: Morini Sergio , Continenza Maria A. , Ricciardi Giuseppe , Gaudio Eugenio , Pannarale Luigi 
Published: April 2004

AbstractThis work investigated the origin and development of microcirculation in the rat humeral head and the expression of vascular endothelial growth factor (VEGF) as a factor supporting the vascular growth and the development of the secondary ossification centers. Sixty rats aging 1, 3–4, 6–8, 11, and 21 days, 5 weeks, and 4 and 8 months were used. Samples of humeral head were collected for histolgy and immunohistochemistry for VEGF. Some animals were perfused with Mercox resin in order to obtain vascular corrosion casts (vcc) observed by scanning electron microscopy (SEM). No cartilage canals were present at birth. At 6 days postnatal, blood vessels coming from the perichondrium and the region near the capsule attachment invaded the cartilage; at 11 days postnatal, signs of calcification were present and within the third week some bone trabeculae were formed. Just before the vascular invasion of the epiphysis, a positive reaction for VEGF was localized in chondrocytes of the epiphyseal cartilage close to the capsule insertion. During the development and expansion of the secondary ossification center, VEGF expression was higher in chondrocytes but decreased when epiphysis was diffusely ossified. VEGF was expressed also by mesenchymal cells present in and around the fibrous tissue where the secondary ossification center will develop. SEM vcc confirmed that vessels penetrating into the epiphysis arose merely from the periosteal and the capsular networks, and vascular connections with the diaphyseal circulation were not evident. These observations demonstrated that VEGF production by chondrocytes begun some days after birth, supported the rapid vascular growth from the surrounding soft tissues, and was chronologically related to the development of the secondary ossification center in rat proximal humerus. Finally, the possible role of VEGF as mediator of angiogenesis and, at least indirectly, as a trigger factor also in the ossification and the bone remodeling of the secondary ossification centers has been discussed. Anat Rec Part A 278A:419–427, 2004. © 2004 Wiley‐Liss, Inc.
Mitochondrial structure in steroid‐producing cells: Three‐dimensional reconstruction of human Leydig cell mitochondria by electron microscopic tomography
Authors: Prince Frederick P. , Buttle Karolyn F. 
Published: April 2004

AbstractMitochondria of human Leydig cells were reconstructed in three dimension utilizing the technique of electron microscopic tomography to obtain a better understanding of the topology of the internal membrane system and the relationship of these cristae to the inner boundary membrane (IBM). Cristae structure, in many respects, is consistent with previous tomographic studies from typical mitochondria, i.e., mitochondria from nonsteroid‐producing cells. Cristae are diverse in form, with well‐defined lamellar cristae interconnected to pleomorphic and tubular regions. Occasional fenestrations are present in the lamellar regions. Also consistent with other mitochondria studied by tomography, the openings of the cristae to the IBM (referred to as crista junctions) are roughly circular or elliptical and approximately 20–25 nm in diameter. Morphological contact sites between the outer mitochondrial membrane and IBM are also present. Cristae membranes in these steroid‐producing mitochondria are often found in close proximity to the IBM. Unique to steroid‐producing mitochondria is a form of the cristae in which multiple lamellae are in very close apposition, previously defined as the lamellar association. Tomographic reconstructions of the lamellar association reveal that these well‐organized membranes also open to the IBM via crista junctions. These regions of closely apposed lamellar cristae are also interconnected and display small tubular extensions from the lamellae. The current study is the first electron microscopic tomography study of mitochondria from steroid‐producing cells. The results show the cristae interconnect to form an extensive internal membrane system, which is perhaps better termed the cristae compartment. This internal membrane system is notable due to the high surface area with few small openings to the IBM. Such a morphology is more analagous to the thylakoid membrane system of chloroplasts than the long‐standing view of mitochondrial cristae. The significance of the lamellar association form of the cristae is unknown. Anat Rec Part A 278A:454–461, 2004. © 2004 Wiley‐Liss, Inc.
Three‐dimensional computational reconstruction of lateral skull base with plastinated slices
Authors: Qiu Ming‐Guo , Zhang Shao‐Xiang , Liu Zheng‐Jin , Tan Li‐Wen , Wang Yu‐Su , Deng Jun‐Hui , Tang Ze‐Sheng 
Published: April 2004

AbstractThe goals of this study were to build the 3D reconstructed model of lateral skull base and to explore the spatial relationships of the important structures for providing the morphological basis for lateral skull base surgery and clinical image diagnosis. Blocks with edges of about 80 mm containing the lateral skull base region and adjacent structures were sawn out from both sides of the heads and sectioned on transverse plane at a thickness of 700 μm using a plastination technique. On an SGI workstation, a Contours‐Marching cubes algorithm was selected to reconstruct the 3D model of the lateral skull base. Accurate alignment of the structures in the serial macroscopic sections was obtained by the employment of the plastination technique. The quality of the reconstructed images was distinct and perfect, specifically, the spatial positions and complicated adjacent relationships of various structures of the lateral skull base can be shown in direct viewing when they are displayed in background of the cranial bony substance. The time spent in displaying or rotating one image including 50 sections was 1.5 sec; all reconstructed structures can be represented individually or jointly and rotated in any plane. The plastination technique and computer‐aided 3D reconstruction have an obvious advantage in the study of the complex anatomy of the lateral skull base. Plastination technique provides cross‐section images of a higher resolution than those obtained from CT scanning. The computerized 3D reconstruction is important in studying the spatial anatomy of the lateral skull base and can serve as a standard for models created with other techniques. Anat Rec Part A 278A:437–442, 2004. © 2004 Wiley‐Liss, Inc.