bluuebunny/crossref_metadata_2025_split huggingface dataset:
Biodegradable polyester composites reinforced with short abaca fiber
Authors: Shibata Mitsuhiro , Takachiyo Kei‐Ichiro , Ozawa Koichi , Yosomiya Ryutoku , Takeishi Hiroyuku 
Published: August 2002

AbstractThe mechanical properties of poly(3‐hydroxybutyrate‐ co‐3‐hydroxyvarelate) (PHBV) composites, reinforced with short abaca fibers prepared by melt mixing and subsequent injection molding, were investigated and compared with PHBV composites reinforced with glass fiber (GF). The influences of fiber length, fiber content, and surface treatment of the natural fiber on the mechanical properties were evaluated. Regarding fiber length, the tensile properties had a maximum at a fiber length of about 5 mm. The flexural properties of the PHBV/abaca composite were improved by the surface treatment of abaca with butyric anhydride and pyridine for 5 h because of the increase of interfacial adhesiveness between the matrix polyester and the surface‐esterified fiber, as is obvious from the SEM micrographs. The flexural and tensile properties of PHBV/treated abaca composite were comparable to those of PHBV/GF composite, except for tensile modulus, compared with the same weight fraction of fiber. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 85: 129–138, 2002
A novel highly copper(II)‐selective chelating ion exchanger based on poly(glycidyl methacrylate‐co‐ethylene dimethacrylate) beads modified with aspartic acid derivative
Authors: Horák Daniel , Beneš Milan J. , Gumargalieva Klara , Zaikov Guennadi 
Published: August 2002

AbstractAnchoring the hydroxyaspartic acid onto poly(glycidyl methacrylate‐co‐ethylene dimethacrylate) (poly(GMA‐co‐EDMA)) beads or epoxysuccinic acid onto ammonium‐modified poly(GMA‐co‐EDMA) beads resulted in a novel chelating resin, which contained up to 0.37 mmol of the ligand per gram of resin. Batch extraction experiments showed a very high selectivity for Cu2+ over Zn2+ and Cd2+ ions in buffered solutions under competitive conditions. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 913–916, 2001
Studies on the strength and wear resistance of tetrapod‐shaped ZnO whisker–reinforced rubber composites
Authors: Zhou Zuowan , Liu Shikai , Gu Lixia 
Published: August 2002

AbstractZinc oxide whisker with a tetrapod shape was treated with a coupling agent using an orthogonal design and was mixed into the substrate of natural rubber to obtain the composites. The results of the experimental tests show that the tensile strength of the composites progressively increases with an increased amount of the related whisker. The experiments also indicate that the rubber reinforced by the tetrapod‐shaped ZnO whisker is distinct isotropy. The wear tests demonstrate that the composites containing ZnO whisker appear to have good wear‐resistance behavior. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1520–1525, 2001
Calculation of alcohol‐acetone‐cellulose acetate ternary phase diagram and their relevance to membrane formation
Authors: Hao Ji Hua , Wang Shichang 
Published: August 2002

AbstractABSTRACTAlcohol‐acetone‐cellulose acetate phase diagrams incorporated with methanol, ethanol, and isopropanol as nonsolvents are calculated according to a new form of the Flory–Huggins equation. Nonsolvent–cellulose acetate interaction parameters are measured by swelling experiments. Concentration‐dependent nonsolvent–solvent interaction parameters are obtained by vapor–liquid equilibrium and the Wilson equation. It is shown that alcohol is a week coagulant compared with water, and water > methanol > ethanol > isopropanol for cellulose acetate. The phase diagrams characteristic of acetone‐cellulose acetate combined with water, methanol, ethanol, and isopropanol as nonsolvents is different, which leads to the different morphological structure of a cellulose acetate membrane. The structure of a water coagulated membrane has large macrovoids from liquid–liquid phase separation. A methanol coagulated membrane has a honeycomb‐like structure from spinodal microphase separation. An ethanol or isopropanol coagulated membrane has a thicker, dense top layer from the delay time phase separation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1650–1657, 2001
Preparation and characterization of nanofiltration composite membranes using polyacrylonitrile (PAN). I. preparation and modification of PAN supports
Authors: Oh Nam‐Wun , Jegal Jonggeon , Lee Kew‐Ho 
Published: August 2002

AbstractPolyacrylonitrile (PAN) supports useful for the formation of nanofiltration (NF) composite membranes were prepared from PAN solutions in N‐methylpyrrolidone (NMP), using a phase‐inversion method. The compositions of the PAN/NMP solutions used were as follows: 10/90, 15/85, and 20/80 (in wt %). The PAN supports were treated with various concentrations of NaOH aqueous solutions (0.1, 0.5, 1, and 2 mol) for certain periods of times (0.5, 1, 2, and 3 h) in order to modify their surface chemically and morphologically. The characteristics of the supports, modified or unmodified, were carefully studied. The morphology of those were observed with field‐emission scanning electron microscopy (FESEM) and atomic force microscopy (AFM). The change of the chemical structure of those by the NaOH treatment was studied using FTIR–ATR spectroscopy and ESCA. The permeation properties of those were also determined at 1–5 bar of operation pressure using a PEG 35,000 aqueous feed solution. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1854–1862, 2001
Thermodynamic work of adhesion and peel adhesion energy of dimethoxysilyl‐terminated polypropylene oxide/epoxy resin system jointed with polymeric substrates
Authors: Okamatsu Takahiro , Yasuda Yushiro , Ochi Mitsukazu 
Published: August 2002

AbstractThe characterization of the interfacial surface of a dimethoxysilyl‐terminated polypropylene oxide (DMSi–PPO)/diglycidylether of bisphenol A (DGEBA) system, which has the phase structure of DGEBA particles in a DMSi–PPO matrix, was investigated by using model joints with polymeric substrates. The surface free energy (γ) of the DMSi–PPO/DGEBA system had varied with the γ of each substrate. When the system contacted to low surface free energy materials such as Teflon, polypropylene, and polyethylene, the γ of the system showed about 14.3–31.6 mJ/m2; on the other hand, when the system contacted to high surface free energy substrates such as polyethylene–telephthalate and polyimide, the γ of the system showed 50.4 and 64.6 mJ/m2, respectively, because the concentration of the DGEBA as a polar component in the system changed around these interfaces. In the low surface energy substrates used, the actual peel adhesion energy value was in good agreement with the thermodynamic work of adhesion (Wa) determined independently. However, in the high surface energy materials used, the peel adhesion energies were 103–104 times larger than Wa because the energy was dissipated viscoelastically at the jointed points. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1920–1930, 2001
Ring‐opening polymerization of epichlorohydrin and its copolymerization with other alkylene oxides by quaternary catalyst system
Authors: Xie Hong‐Quan , Guo Jun‐Shi , Yu Guang‐Quan , Zu Jiang 
Published: August 2002

AbstractAn effective quaternary catalyst consisting of trialkyl aluminum, phosphoric acid, electron donor, and water for ring‐opening polymerization of epichlorohydrin (ECH), as well as its copolymerization with ethylene oxide (EO), propylene oxide (PO), and allyl glycidyl ether (AGE) to obtain elastomers, were studied. We investigated the optimum composition for the quaternary catalyst; the character of the catalyst; the reactivity of the four alkylene oxides during homopolymerization and copolymerization; the behavior of ECH, EO, and PO during terpolymerization; and glass transition temperatures of the copolymer and terpolymers. The results showed that the nitrogen‐containing electron donors are suitable as the third component, whereas oxygen‐containing electron donors are not. Water as the fourth component can increase the molecular weight of the homopolymer and copolymers of ECH. According to the polymerizability of tetrahydrofuran with the quaternary catalyst and the reactivity ratios of the four alkylene oxides, the quaternary catalyst was assumed to be of a coordinated anionic type. The reactivity ratios for these four alkylene oxides were determined to be EO > PO > AGE > ECH. They were verified by terpolymerization of ECH, EO, and PO. The glass transition temperature of the terpolymer exhibits a minimum value at nearly 3:1 molar ratio of PO to EO, when the molar ratio of ECH used is constant at the beginning of terpolymerization. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2446–2454, 2001
Properties and morphologies of PVC/nylon terpolymer blends
Authors: Lian Yongxiao , Zhang Yong , Peng Zhonglin , Zhang Xiangfu , Fan Ruliang , Zhang Yinxi 
Published: August 2002

AbstractA new kind of blends of polyvinyl chloride (PVC)/nylon terpolymer was reported in this article. Two compatibilizers were used in this study: one is a terpolymer of ethylene–n‐butyl acrylate–monoxide (EnBACO); the other is terpolymer of EnBACO grafted with maleic anhydride (EnBACO‐g‐MAH). The observation of scanning electron microscope (SEM) reveals that the PVC/nylon terpolymer blends have a two‐phase structure; and the nylon terpolymer phase is the continuous phase, and PVC domains in the PVC/nylon terpolymer/EnBACO‐g‐MAH blends have fine dispersion over a broad range of the PVC/nylon terpolymer ratio. EnBACO‐g‐MAH is more compatible with the nylon terpolymer than EnBACO. EnBACO and EnBACO‐g‐MAH have different effects on the glass transition temperatures of the PVC phase and nylon terpolymer phase in the blends. The notched Izod impact strength, tensile strength, elongation at break, Vicat softening temperature (VST), and melt flow index (MFI) critically depend on PVC/nylon terpolymer ratio, the kinds and concentration of the compatibilizers. The PVC/nylon terpolymer/EnBACO‐g‐MAH blends display a good combination of high toughness, high flowability, and high VST under low load. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2823–2832, 2001
Transport of Cu(II) ions through charged cation‐exchange membranes
Authors: Ersöz M. , Çengeloğlu Y. , Kir E. , Koyuncu M. , Yazicigil Z. 
Published: August 2002

AbstractTransport of Cu(II) ions through polysulfonated cation‐exchange membranes under Donnan dialysis conditions was studied as a function of the pH gradient. The used charged membranes are homogeneous (polysulfone composition) and heterogeneous (polysulfone with polyester support) structures which are strongly acidic cation‐exchange microporous‐type membranes. The flux increases with decreasing of the pH gradient, which is influenced by the transport of copper ions. The quantitative relations were obtained which describe the time dependence of the transport system with the equilibrium distribution and the results were correlated with the flux data as well as with the membrane structure. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 421–427, 2001
Thermal fractionation and crystallization enhancement of silane‐grafted water‐crosslinked low‐density polyethylene
Authors: Shieh Yeong‐Tarng , Chen Jui‐Shui , Lin Chung‐Chin 
Published: August 2002

AbstractThermal fractionations performed using differential scanning calorimetry (DSC) to characterize the heterogeneities in molecular structures of low‐density polyethylene (LDPE), silane‐grafted LDPE (G‐LDPE), and silane‐grafted water‐crosslinked LDPE with gel fractions of 30 and 70 wt % are reported. In regular DSC analyses, LDPE, G‐LDPE, and the low gel fraction of crosslinked samples (30 wt %) give one broad endothermic peak at ∼110 °C, whereas the high gel fraction of crosslinked samples (70 wt %) give overlapped multiple endothermic peaks in a much broader temperature range. After thermally fractionated in the range 60–145 °C, LDPE, G‐LDPE, and the low gel fraction samples give five to six endothermic peaks in the low‐temperature range, whereas the high gel fraction samples give nine peaks, with three additional peaks appearing in the high‐temperature range. These multiple peaks correspond to fractions of different molecular structures, with the additional peaks for the high gel fraction samples corresponding to the fraction of molecular segments with low or no branching. This fraction of molecular segments is increasingly extruded out of the gel region with increasing gel fraction by crosslinking and leads to an enhancement of crystallization of the sample. This crystallization enhancement behavior is also demonstrated by the X‐ray diffraction data and polarized optical micrographs. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 591–599, 2001
Viscoelastic behavior of anhydride‐cured epoxy system initiated by thermal latent catalyst
Authors: Kwak Geun‐Ho , Park Soo‐Jin , Lee Jae‐Rock 
Published: August 2002

AbstractThe thermal latency and viscoelastic behavior during the cure of a new catalytic (N‐benzylpyrazinium hexafluoroantimonate) anhydride‐cured epoxy system were studied with differential scanning calorimetry and a rheometer under isothermal conditions. The gelation time was obtained from the evaluation of the storage modulus, loss modulus, and damping factor. The temperature dependence on the reaction time was described by the Arrhenius expression, and the crosslinking activation energy was determined from the Arrhenius plot based on the gelation time and reaction temperature. The gelation time and crosslinking activation energy characterized from rheological behaviors increased with increasing anhydride composition and showed a maximum value with a mixing ratio of 0.65, which was due to the compact crosslinking network without a side reaction in the ratio. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 646–653, 2001
Differential scanning calorimetry analysis of silicon‐containing and phosphorus‐containing segmented polyurethane. I—Thermal behaviors and morphology
Authors: Lin Ming‐Fung , Shu Yao‐Chi , Tsen Wen‐Chin , Chuang Fu‐Sheng 
Published: August 2002

AbstractThis article investigated thermal transition and morphology utilizing differential scanning calorimetry (DSC), which was performed on silicon‐containing and phosphorus‐containing segmented polyurethane (Si‐PU and P‐PU). The hard segments of those Si‐PU and P‐PU polymers investigated consisted of 4,4′‐diphenylmethane diisocyanate (MDI) and diphenylsilanediol (DSiD), MDI, and methylphosponic (MPA), respectively. The soft segment of those polymers comprised polytetramethylene ether glycol, with an average molecular weight of 1000 or 2000 (PTMG 1000 and PTMG 2000, respectively). Several thermal transitions appeared for on the Si‐PU and P‐PU polymers, reflecting both the soft‐segment and hard‐segment phases. The Si‐PU and P‐PU polymers with a lower hard‐segment content exhibited a high degree of phase separating as indicated by the constancy of both the soft‐segment glass transition temperature (Tgs) and the breadth of transition zone (ΔB). The polymers in which PTMG 2000 was used as the soft segment generally exhibited a crystalline melting endotherm about 10°C, while crystallization usually disappeared upon melt quenching. The hard segments of the Si‐PU and P‐PU polymers displayed multiple endotherms. The first endotherm was related to a short‐range ordering of the hard segment domain (Region I), and the second endotherm was ascribed to a long‐range ordering of the domain (Region II). The wide‐angle X‐ray demonstrated that the structure in Region I and Region II was almost completely amorphous. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3489–3501, 2001
Differential scanning calorimetry analysis of silicon‐containing and phosphorus‐containing segmented polyurethane. II Annealing effect
Authors: Shu Yao‐Chi , Lin Ming‐Fung , Tsen Wen‐Chin , Chuang Fu‐Sheng 
Published: August 2002

AbstractThe effect of thermal annealing on the multiple endothermic behavior and morphological changes in the silicon‐containing and phosphorus‐containing segmented polyurethane (Si‐PU and P‐PU) has been studied by differential scanning calorimetry (DSC). In the amorphous hard segments of the Si‐PU and P‐PU polymers that were annealed below T2, both the T1 temperature, and magnitude of T1 endotherm increased linearly as a function of the logarithmic annealing time (log ta). This result demonstrated that the endothermic behavior (T1 endotherm) is typical of enthalpy relaxation resulting from the physical aging of the amorphous hard segment. Furthermore, the P‐PU polymer was unstable than the Si‐PU polymer due to the fact that the phosphorus‐containing hard segment produce aged more easily. Dissociation of domains and enthalpy relaxation of hard segments for the Si‐PU polymer was associated with T2 endothermic behavior. However, the enthalpy relaxations of the T2 endothermic behavior for P‐PU polymer was absent, which could be attribute to the behavior of degradation in the temperature range of T2 endotherm. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 3502–3513, 2001
Water stability of syndiotactic poly(vinyl alcohol)/iodine complex film
Authors: Lyoo Won Seok , Yeum Jeong Hyun , Choi Jin Hyun , Song Han‐Chul , Ji Byung Chul , Kim Jae Pil , Noh Tae Hwan , Yoon Woong Jae , Cheong Tae Sik 
Published: August 2002

AbstractThe desorption behavior of iodine in syndiotactic poly(vinyl alcohol) (s‐PVA) with a syndiotactic diad content of 63.1% iodine film in water was investigated in relation to the solubility of s‐PVA in water. Despite a low number‐average degree of polymerization of 900, the degree of solubility of s‐PVA film in water at 80°C was limited to about 10%, whereas atactic poly(vinyl alcohol) (a‐PVA) film was completely soluble at a lower temperature, 50°C. The degree of iodine desorption of s‐PVA/iodine film at a high temperature decreased remarkably compared with that of a‐PVA/iodine film. The fastness of iodine of the drawn s‐PVA/iodine film was far superior to that of the undrawn film. Over a draw ratio of 5, the iodine desorption was suppressed significantly with increasing drawing temperature rather than the draw ratio. In addition, the iodine desorption of postdrawn s‐PVA/iodine film was lower than that of predrawn s‐PVA/iodine film. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 108–113, 2001
Hybrid membranes based on SiO2/polyether‐b‐polyamide: Morphology and applications
Authors: Sforça Maurício L. , Yoshida Inez V. P. , Borges Cristiano P. , Nunes Suzana P. 
Published: August 2002

AbstractHybrid materials were prepared incorporating silica networks by the sol–gel process into the poly(amide‐b‐polyether) block copolymer PEBAX®. PEBAX®/silica hybrids were characterized by transmission electron microscopy, atomic force microscopy, differential scanning calorimetry, and X‐ray diffraction. The pervaporation of phenol from dilute aqueous solutions through hybrid membranes was investigated. Films prepared with lower silica contents showed better dispersed inorganic networks and were more selective in the pervaporation of phenol/water solutions. Films prepared with higher silica contents had a clear phase‐separated morphology with lower performance in pervaporation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 178–185, 2001
Characteristics of medical polymer based on an epoxy resin system—Curing reaction characteristics of biphenol epoxy monomer with phenolic functional hardeners
Authors: Kim S. W. , Lu M. G. , Shim M. J. 
Published: August 2002

AbstractThe reaction kinetics of a biphenyl epoxy/polyol system was characterized by an isoconversional mode under dynamic conditions using differential scanning calorimetry (DSC) measurements. The results showed that the curing of epoxy resins involves different reaction stages and the values of activation energy is dependent on the degree of conversion. At the initial stage of cure, the phenol hydroxyl‐epoxy reaction is predominant, then the hydroxyl group generated during curing can catalyze the reaction. The results were supported by the isothermal experiments. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1495–1503, 2001
Studies on urethane‐modified alumina‐filled polyesteramide anticorrosive coatings cured at ambient temperature
Authors: Ahmad Sharif , Ashraf S. M. , Hasnat Abul , Yadav S. , Jamal A. 
Published: August 2002

AbstractCoatings prepared from polyesteramide resin synthesized from linseed oil, a renewable resource, have been found to show improved physicomechanical and anticorrosive characteristics. These properties are further improved when aluminum is incorporated in the polyesteramide resin. The coatings of this resin are generally obtained by baking at elevated temperatures. With a view toward the use of linseed oil, as a precursor for the synthesis of polyesteramide resins and to cure their coatings at ambient temperature, toluylene diisocyanate (TDI) was incorporated into polyesteramide and alumina‐filled polyesteramide in varying proportions to obtain urethane‐modified resins. The latter resins were found to cure at room temperature. The broad structural features of the urethane‐modified polyesteramide and alumina‐filled polyesteramide were confirmed by FTIR and 1H–NMR spectroscopies. Scratch hardness; impact resistance; bending resistance; specular gloss; and resistance to acid, alkali, and organic solvents of the coatings of these resins were determined by standard methods. Physicomechanical and anticorrosive properties, specular gloss, and thermal stability of the urethane‐modified alumina‐filled polyesteramide coatings were found to be at higher levels among these resins. It was found that TDI could be incorporated in polyesteramide up to only 6 wt %, such that above this loading its properties started to deteriorate, whereas alumina‐filled polyesteramide could take up to 10 wt % TDI. Explanation is provided for the increase in scratch hardness and impact resistance above 6 and 10 wt % addition of TDI in polyesteramide and alumina‐filled polyesteramide, respectively, as well as for the decrease in flexibility and resistance to solvents, acid, and alkali of coatings of these resins above these limits of TDI addition. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1855–1865, 2001
Tensile properties of silkworm silk obtained by forced silking
Authors: Pérez‐Rigueiro J. , Elices M. , Llorca J. , Viney C. 
Published: August 2002

AbstractBave was acquired by the forced silking of three Bombyx mori silkworms, and its tensile properties were characterized. The material collected from any given silkworm yielded reproducible force‐displacement plots, which were qualitatively similar to the plots obtained from silk collected from the other silkworms. This uniformity contrasts with the highly variable properties exhibited by silk which had been reeled from degummed cocoons. Scanning electron microscopy images were used to obtain information about the sample cross‐sectional area, so that force‐displacement plots could be rescaled as stress–strain curves. Surprisingly, the scatter in the tensile properties increases after such rescaling. This finding can be explained in terms of the sericin coating of the bave (which contributes to the cross‐sectional area but not significantly to the load‐bearing capacity) having a variable thickness. When the sericin coating was eliminated by a degumming treatment, it was found that the fibers showed more consistent cross‐sectional areas. Therefore, stress–strain curves of forced B. mori silk are reproducible, provided that force‐displacement data are rescaled by the correct cross‐sectional area. Finally, the Weibull parameters of the forced silk were determined. The Weibull modulus, m, has a value of 13.0 ± 0.3, which is more than double the value obtained previously from silk reeled from a cocoon, demonstrating that the process of degumming cocoons has a detrimental effect on the distribution of defects in the silk microstructure. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1928–1935, 2001