bluuebunny/crossref_metadata_2025_split huggingface dataset:
Drawing properties of ultrahigh molecular weight polyethylene fibers prepared at varying formation temperatures
Authors: Yeh Jen‐Taut , Lin Yue‐Tang , Jiang Huang‐Bin 
Published: December 2003

AbstractThe values of the percentage crystallinity, melting temperature, birefringence, and cross‐sectional area of ultrahigh molecular weight polyethylene (UHMWPE)/low MWPE (LMWPE) as‐prepared fiber specimens are reduced consistently as the formation temperatures decreased from 60 to 0°C. Much more sparse structures with significantly larger voids are found on the fractured surfaces of those as‐prepared fibers that were prepared at higher formation temperatures than those prepared at lower formation temperatures. The cross sections of the as‐prepared fiber specimens gradually change from an oblate to a nearly circular to an uneven circular shape as the formation temperatures are reduced from 60 to 10 to 0°C, respectively. It is worth noting that the achievable draw ratios (Dra) of the as‐prepared fibers reach maximum when they are prepared at an optimum formation temperature of 10°C. Moreover, the Dra values of the as‐prepared fiber (UL10) specimens can be further improved by using a two‐stage drawing process, wherein the temperature used in the second drawing stage (Tsec) is higher than 95°C. In fact, the optimum Tsec of the two‐stage drawn UL10 fiber specimens increases significantly from 105 to 115°C as the first‐stage draw ratio (Dlr) values increase from 20 to 40, respectively. The birefringence values, tensile strengths, and moduli of one‐ and two‐stage drawn UL10 fiber specimens increase consistently with increasing draw ratios, although the increasing rate of these values is gradually reduced as the draw ratios are greater than certain values. In contrast, at a constant draw ratio, the two‐stage drawn UL10 fiber specimens drawn at a higher Tsec always exhibit higher values of birefringence, tensile strengths, and moduli than those with the same Dlr but drawn at a lower Tsec. Moreover, at a constant draw ratio, the birefringence values, tensile strengths, and moduli of the fiber specimens drawn at a fixed optimum Tsec reach the maximum when they are first drawn up to an optimum Dlr of about 50. In fact, by using the proper optimum Tsec and Dlr, the tensile strengths and moduli of the two‐stage drawn UL10 fiber specimens can reach more than 11 and 155 GPa, respectively. The possible mechanisms accounting for these interesting properties are proposed in this study. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1559–1570, 2004
Crosslinking of polyvinyl chloride by electron beam irradiation in the presence of ethylene–vinyl acetate copolymer
Authors: Wang Shifeng , Zhang Yong , Zhang Yinxi , Zhang Changming , Li Enjun 
Published: December 2003

AbstractElectron beam (EB) irradiation of polyvinyl chloride (PVC) was carried out in the presence of three different ethylene–vinyl acetate copolymers (EVA). The mechanical properties of the original and irradiated blends were tested. The gel content measurement, chlorine loss upon electron irradiation, and gel permeation chromatograph (GPC) were used to characterize the effect of EVA on the irradiation behavior of PVC/EVA blends. The content and the chemical structure of EVA in the blends had considerable effects on the mechanical properties and gel content of the blends. The incorporation of EVA into PVC blend can increase the gel content and reduce chlorine loss of the blends. The GPC analysis of the soluble part in the irradiated PVC samples showed that the addition of EVA into the PVC blend lowered the polydispersity of molecular weight of PVC. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1571–1575, 2004
Damping of vinyl acetate–n‐butyl acrylate copolymers
Authors: Chu Hou‐Hsein , Lee Chi‐Ming , Huang W. G. 
Published: December 2003

AbstractA photopolymerization process at room temperature was devised to copolymerize vinyl acetate (VAc) and n‐butyl acrylate (BA) mainly to prepare rubber‐like damping sheet bearing pressure‐sensitive adhesive property in this study. The investigations using both the differential scanning calorimeter and rheometric dynamic analysis show the existence of two glass transition temperatures for each copolymer. The scanning electron microscopic pictures reveal that the degree of microphase separation increases with increasing annealing time at 70°C. It was suggested that the rubbery domain (formed by the PBA blocks) disperses in the glassy domain (constituted by the PVAc blocks), making an effective damping entity. Excellent damping was observed for the copolymer samples, with the tanδ peak values as high as 1.76–1.80 at a certain temperature range and with tanδ> 0.3 at quite wide temperature ranges. In addition, the copolymers containing more VAc tend to have the higher damping. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1396–1403, 2004
Linear polymers with sulfur in the main chain. II. Synthesis of polyesters by interfacial polycondensation of bis(4,4′‐hydroxyphenyl)sulfide with several aliphatic acid dichlorides and their properties
Authors: Hirano Hiroshi , Watase Seiji , Tanaka Mitsuaki 
Published: December 2003

AbstractThe synthesis and properties of sulfur‐containing polyesters derived from bis(4,4′‐hydroxyphenyl)sulfide (TDP) and various acid dichlorides (AC) have been studied to evaluate the effect of the incorporation of sulfur in the main chains of polyesters. Polyesters derived from TDP and AC (with methylene numbers of 2–10) were synthesized by interfacial polycondensation in a 1,1,2,2‐tetrachloroethane /water mixture using tetra‐n‐butyl ammonium bromide as a phase transfer catalyst. Through the use of gel permeation chromatography, it was determined that the polyesters thus obtained had high molecular weights. The thermal properties of the polyesters including the TDP moiety were evaluated by thermogravimetry/differential thermal analysis and by differential scanning calorimetry. The analyses indicated that the polyesters including the TDP moiety were crystalline polymers with relatively high heat resistance. These polyesters were found to show an odd–even effect with the glass transition temperature and the melting point based on the methylene numbers. The tensile strength and storage modulus decreased with the methylene numbers. It was further found that the polyesters evidenced excellent barrier properties towards oxygen gas having an odd–even effect. In particular, it was shown that the polyesters with methylene numbers of 3, 4, 6, and 8 of methylene units have lower oxygen permeability than poly(ethylene terephthalate) (PET).©2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1865–1872, 2004
Inhibitor radicals in styrene polymerization
Authors: Motyakin M. V. , Wasserman A. M. , Stott P. E. , Zaikov G. E. 
Published: December 2003

AbstractStable radicals derived from inhibitor molecules were detected in the process of styrene polymerization. N‐(1,4‐dimethylpentyl)‐4‐nitroso‐aniline and 2,4‐dinitrophenol inhibitors were shown to produce nitroxyl radicals. Phenoxyl radicals come from 4‐benzylidene‐2,6‐di‐tert‐butyl‐cyclohexa‐2,5‐dienone. The radical structures were determined. The kinetics of radical formation was studied. These radicals can participate in the process of living radical polymerization and significantly affect the kinetics of polymerization. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1599–1603, 2004
Influence of processing on structure of β‐nucleated poly(propylene) fibers
Authors: Broda Jan 
Published: December 2003

AbstractFibers colored with quinacridone pigment spun at low take‐up velocities were obtained. The spun fibers, with a very high β‐form content, were drawn at room temperature and at a temperature of 120°C at different draw ratios. They were then heat stabilized at different temperatures, ranging from 140 to 150°C for different time intervals. As a result of drawing, the transition from β to mesophase, as well as that from β to α, was observed. The β to mesophase transition results from cold drawing at room temperature, while the β to α transition results from drawing at 120°C. In both cases, the significant decrease of β‐form content occurs at the low draw ratio of 2. At higher draw ratios, the β‐form content gradually decreases, and at a draw ratio of 7 the β‐form disappears altogether. As a result of heat stabilization, the β to α transformation was observed. The first change of the β‐form content was noticed at 140°C. For fibers stabilized at temperatures above 140°C, the decrease of the β‐form content is more significant and increases with the increase of the stabilization temperature. At 150°C, a rapid drop of the β‐form content occurs after only 3 min, and after a few more minutes the β‐form disappears. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1413–1418, 2004
Synthesis and electrorheology of potato starch phosphate
Authors: Park Dong P. , Sung Jun H. , Kim Chul Am , Choi Hyoung J. , Jhon Myung S. 
Published: December 2003

AbstractPotato starch phosphate (PSP) particles were synthesized via an esterification process of potato starch with a mixture of various concentrations of phosphoric acid and urea. The electrorheological (ER) characteristics of the synthesized PSP particles, suspended in a silicone oil, were examined. The PSP granule‐based ER fluid exhibited typical ER behavior, possessing a nonvanishing yield stress under an applied electric field. Enhanced polarization and higher yield stresses were observed as the content of phosphate groups in the starch increases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1770–1773, 2004
Thiophosphoryl disulfides as crosslinking agents for chloroprene rubber
Authors: Das Amit , Naskar Nityananda , Basu Dipak Kumar 
Published: December 2003

AbstractThe objective of this investigation was the determination of a suitable substitute for ethylene thiourea (ETU), a well‐known vulcanizing agent for polychloroprene rubber (CR). Unfortunately, ETU is a potent carcinogenic compound, and so its replacement is needed. The efficacy of several thiophosphoryl disulfides as crosslinking agents for CR, either alone or in combination with other compounds, was examined. It was shown that bis(diisopropyl)thiophosphoryl disulfide (DIPDIS) and bis(dicyclohexyl)thiophosphoryl disulfide (DCHDIS), being ecofriendly, could be replacements. Additionally, these thiophosphoryl compounds were shown to provide significant antioxidant protection. CR vulcanizates containing DIPDIS or DCHDIS exhibited higher tensile strengths than those containing ETU. Bis(3‐ethoxysilylpropyl) tetrasulfide imparted to CR vulcanizates a notable modulus, which was comparable to that obtained with ETU‐cured products. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1913–1919, 2004
Coating of porous silica beads by in situ polymerization/crosslinking of 2‐hydroxypropyl β‐cyclodextrin for reversed‐phase high performance liquid chromatography applications
Authors: Carbonnier B. , Janus L. , Lekchiri Y. , Morcellet M. 
Published: December 2003

AbstractPorous silica beads were coated with a crosslinked β‐cyclodextrin polymer by in situ polymerization/crosslinking of 2‐hydroxypropyl β‐cyclodextrin with 1,6‐hexamethylenediisocyanate in anhydrous dimethylsulfoxide. This method was developed for the preparation of reversed‐phase high performance liquid chromatography stationary phases. The mass of polymer immobilized onto the silica surface was controlled by the amount of coupling agent, 1,6‐hexamethylenediisocyanate, added during the coating process. The influence of the polymer coating on the physical features of the beads was investigated by means of nitrogen adsorption/desorption methods, scanning electron microscopy and energy dispersion X‐ray analysis. The column lifetime was found to be primarily dependent on the extent of crosslinking of the stationary phase. Moreover, it was demonstrated that the synthesis of highly crosslinked stationary phases with a reasonable column lifetime gave rise to a phase separation of the β‐cyclodextrin polymer. To prove their usefulness as reversed‐phase packing materials, they were used to separate mixtures of nitrophenol positional isomers, four pesticides, and drugs. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1419–1426, 2004
Effect of different film preparation procedures on the thermal, morphological and mechanical properties of pure and calcite‐filled HDPE films
Authors: Kundu Patit P. , Biswas Jagannath , Kim Hyun , Chung Chee‐Won , Choe Soonja 
Published: December 2003

AbstractThe effect of different film preparation procedures on the thermal, morphological and mechanical properties of high density polyethylene (HDPE) films have been studied using differential scanning calorimetry (DSC), wide angle X‐ray diffraction (WAXRD), atomic force microscopy (AFM), scanning electron microscopy (SEM) and ultimate tensile testing. Film preparation procedures included variation in cooling methods, including quenching, forces (fanning) and natural cooling and techniques such as extrusion followed by melt squeezing and compression molding. The heat of fusion (from DSC), the degree of crystallinity (from WAXRD) and the crystallite size (from WAXRD and AFM) were found to be highest for naturally cooled specimens, followed by fan‐cooled and quenched ones. AFM images of surface topology exhibit stacked lamellar morphology for forcefully cooled (fan‐cooled and quenched) samples and spherulitic ‘lozenges’ for naturally cooled ones. The Young's modulus and yield stress [from the universal testing machine (UTM)] were highest for naturally cooled samples, followed by fan‐cooled and quenched ones. Among the calcite‐filled composites, the ‘base film,’ which was prepared by extrusion followed by melt squeezing and natural cooling, exhibited the lowest heat of fusion and degree of crystallinity and a similar crystallite size relative to compression‐molded films. Lower yield stress, tensile strength and Young's modulus and higher elongation at break were observed for the base film in comparison to the naturally cooled composite film. The low degree of crystallinity and crystallite size in the ‘base film’ explain all of its mechanical and morphological properties. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1427–1434, 2004
Volume strain changes of plasticized poly(vinylidene fluoride) during tensile and creep tests
Authors: Cangemi L. , Elkoun S. , G'Sell C. , Meimon Y. 
Published: December 2003

AbstractThe volume strain changes of plasticized poly(vinylidene fluoride) during tensile and creep tests were characterized. A negative volume strain was observed. This phenomenon was ascribed to compaction taking place during mechanical testing, which further delayed the onset of plastic instability and, therefore, the cavitation process. It was suggested that this compaction was caused by the orientation of amorphous chain segments leading to material densification. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1784–1791, 2004
Study on isotactic polypropylene/zinc‐neutralized sulfonated ethylene propylene diene monomer rubber/CaCO3 ternary blends
Authors: Zheng Mingjia , Li Huilin 
Published: December 2003

AbstractThe morphological structure and mechanical properties of isotactic polypropylene (PP)/zinc‐neutralized sulfonated ethylene propylene diene monomer rubber (ZnSEPDM)/CaCO3 blends were studied. PP/ZnSEPDM/CaCO3 blends were prepared through two different sequences. A: Blending PP with ZnSEPDM, then adding CaCO3; B: Blending ZnSEPDM with CaCO3, then adding PP. The blending sequence has substantial influence on the mechanical properties. SEM micrographs and X‐ray photoelectron spectrometry indicate that the CaCO3 filler is encapsulated by ZnSEPDM in those blends prepared through sequence B, which caused an extra increase of impact strength. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1635–1640, 2004
Dry‐peelable temporary protective coatings from waterborne self‐crosslinkable sulfourethane–silanol dispersions
Authors: Lewandowski Kevin , Krepski Larry R. , Mickus Daniel E. 
Published: December 2003

AbstractNovel temporary protective coatings were prepared by the addition of release additives to waterborne polyurethane dispersions. New types of self‐crosslinkable sulfourethane–silanol (SUS) dispersions were utilized as the peelable coatings. These dispersions are stable, low‐volatility organic chemical (VOC) waterborne dispersions that spontaneously crosslink upon drying without extra additives or processing steps. Tensile strengths up to 6000 psi with elongations between 300–600% were obtained for the crosslinked films. The adhesion of the films to a variety of substrates can be controlled by the addition of hydrophilic additives, including glycerol, oligomers of glycerol, and poly(ethylene glycol) derivatives. Alternatively, hydrophobic additives that are water dispersible, such as paraffin waxes and sulfated castor oil, can also be used to control adhesion. In addition, this technique can be utilized for the release of films derived from a wide variety of waterborne urethane dispersions, including carboxylated polyurethane ureas. The removable coatings are useful for the temporary protection of plastic surfaces during thermoforming processes. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1443–1449, 2004
Preparation and characterization of thermosensitive beads with macroporous structures
Authors: Ni Caihua , Wang Zheng , Zhu Xiao Xia 
Published: December 2003

AbstractThermosensitive copolymers of poly(N‐isopropyl acrylamide)‐co‐2‐hydroxyethyl methacrylate (NIPA‐co‐HEMA) macroporous resins were synthesized in the form of beads by inverse suspension polymerization. The copolymerization was carried out in aqueous solutions of the comonomers dispersed by cyclohexane with stabilizers. A series of resins with different molar ratios of NIPA : HEMA, and different crosslinking degrees was obtained. The compositions of the copolymers were determined by elemental analysis. The results showed that the content of HEMA in a copolymer was higher than that of the corresponding feed mixture from which the copolymer was made. IR spectra also confirmed the structure of the copolymers. The porous parameters such as true densities, apparent densities, pore volumes, and porosities of the resins were measured by means of pycnometry. The determination of equilibrium swelling ratios and measurement of differential scanning calibration indicated that the resins exhibited thermosensitivity in aqueous solutions. Finally, the loading of hydroxyl groups was determined by titration. The resins have potential applications as supports in solid‐phase synthesis after being functionalized. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1792–1797, 2004
Study on the dynamic self‐organization of montmorillonite in two phases
Authors: Wang Shaofeng , Hu Yuan , Song Lei , Liu Jie , Chen Zuyao , Fan Weicheng 
Published: December 2003

AbstractPolycarbonate (PC)/acrylonitrile–butadiene–styrene (ABS) polymer alloy/montmorillonite (MMT) and nylon 6 (PA6)/ABS polymer alloy/MMT nanocomposites were prepared using the direct melt intercalation technique. Their structures were characterized by XRD and TEM. The results of TEM show that the silicate layers dispersed differently in two phases. In the PC/ABS/MMT nanocomposite, the silicate layers were self‐organized in the ABS phase, whereas in the PA6/ABS/MMT nanocomposite, the silicate layers were dispersed in both phases but mainly in the PA6 phase. Furthermore, the PC/MMT nanocomposite was melt‐mixed with pure ABS, and the changed morphology of the hybrid with the change of melt‐mixing time was characterized by XRD and TEM, to study the dynamic self‐assembly of clay layers in two phases. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1457–1462, 2004
Study of poly(trimethylene terephthalate) as an engineering thermoplastics material
Authors: Zhang Jialiang 
Published: December 2003

AbstractPoly(trimethylene terephthalate) (PTT) was systematically studied as an engineering thermoplastics material. Crystallization rates, crystalline degrees, and mechanical properties of two commercial PTT polymers and one glass fiber–reinforced PTT compound were investigated and compared with those of poly(butylene terephthalate) (PBT). PTT raw polymers have crystallization temperature (Tc) values around 152°C, and their kneaded polymers show Tc values of about 177°C, about 15°C lower than the values of PBT polymers used in this study. From the exothermic heat values of DSC measurements, both PTT and PBT show the crystalline degree order greater than 30%. Injection‐molded PTT specimens and PBT specimens exhibit crystalline degrees from 18 to 32% and 23.8 to 30%, respectively. PTT polymers show higher tensile and flexural strengths, but lower impact strengths and elongations than those of PBT polymers. The low elongation behavior of PTT does not change with the intrinsic viscosity and the molder temperature. PTT‐GF30 promotes better mechanical properties than those of PBT‐GF30, close to those of PET‐GF30. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1657–1666, 2004
Preparation and characterization of poly(L‐lactide)/ poly(ϵ‐caprolactone) fibrous scaffolds for cartilage tissue engineering
Authors: Zhao Jin , Yuan Xiaoyan , Cui Yuanlu , Ge Quanbo , Yao Kangde 
Published: December 2003

AbstractPolyblend fibrous scaffolds in mass ratios of 100/0, 90/10, 80/20, and 70/30 from poly(L‐lactide) (PLLA) and poly(ϵ‐caprolactone) (PCL) for cartilage tissue engineering were prepared in three steps: gelation, solvent exchanging, and freeze‐drying. Effects of the blend ratio, the exchange medium, and the operating temperature on the morphology of scaffolds were investigated by SEM. PLLA/PCL scaffolds presented an ultrafine fibrous network with the addition of a “small block” structure. Smooth and regular fibrous networks were formed when ethanol was used as the exchange medium. Properties of the scaffolds, such as thermal and mechanical properties, were also studied. The results suggested that the compressive modulus declined as PCL amount increased. The incorporation of PCL effectively contributed to reduce the rigidity of PLLA. Bovine chondrocytes were seeded onto PLLA/PCL scaffold. Cells attached onto the fibrous network and their morphology was satisfactory. This polyblend fibrous scaffold will be a potential scaffold for cartilage tissue engineering. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1676–1684, 2004
UV‐radiation–induced preirradiation grafting of methyl methacrylate onto lignocellulose fiber in an aqueous medium and characterization
Authors: Khan Ferdous , Ahmad S. R. , Kronfli E. 
Published: December 2003

AbstractThe preirradiation method of grafting has been established by ultraviolet radiation. Methyl methacrylate (MMA) was grafted onto jute fiber in an aqueous medium. The variation of graft weight with UV‐radiation time, monomer concentration, and reaction time was investigated. The conversion of monomer into homopolymer and graft copolymer was evaluated. The graft weight passes through a maximum value (∼ 122%) with UV‐radiation time. The optimum value of the monomer concentration was evaluated for maximum degree of grafting. Graft copolymerization of MMA onto lignocellulose fiber significantly increases the elongation at break (∼ 65%) compared to that of the “as‐received” sample. However, a linear decrease on breaking load was observed with the increase of graft weight. The estimation of degree of grafting was achieved using an IR technique by correlating band intensities with the degree of grafting. Considering the water‐absorption property, the grafted sample showed a maximum up to 61% decrease in hydrophilicity compared to that of the as‐received sample. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1667–1675, 2004