bluuebunny/crossref_metadata_2025_split huggingface dataset:
Attempt to reduce bowing distortion in tentering of film
Authors: Yamada Toshiro , Nonomura Chisato 
Published: April 2003

AbstractIn order to solve the problem of the bowing phenomenon in the tentering process of film, the stretching and thermosetting conditions were examined with a poly(ethylene terephthalate) film. The simulated and experimental results confirmed that decreasing or preventing the transmission to the next thermosetting zone of the longitudinal force generated by the transverse stretching, and then restretching the film in the thermosetting zone, effectively reduces the bowing distortion. The following effects were observed: (1) Once the film is cooled after stretching it in a tenter, the different patterns of its deformation behavior can be obtained. The bowing distortion changes remarkably with the temperature of film and the length of the cooling zone. (2) When the temperature of the cooling zone is not higher than the glass transition point, the effect of the cooling zone in reducing the bowing distortion is at its maximum. The longer the cooling zone is, the less the bowing distortion becomes. However, it becomes almost constant when the length of the cooling zone is at least twice the width of the film. (3) When the cooling zone is set up between the stretching and thermosetting zones, the bowing distortion is almost independent of the thermosetting temperature. (4) Relaxation and restretching in the transverse direction in the thermoseting zone influence the bowing distortion: greater relaxation results in greater bowing distortion and greater restretching results in the less bowing distortion. © 1994 John Wiley & Sons, Inc.
Electrically conductive composite of polypyrrole and liquid crystalline copoly(ester‐amide)s
Authors: Bao Jingsheng , Xu Chaochou , Cai Wei , Bi Xian‐Tong 
Published: April 2003

AbstractThe modification of the mechanical properties of polypyrrole (PPY) by electrochemical preparation of conductive composite film from pyrrole (PY) and three kinds of liquid crystalline copoly(ester‐amide)—PEA(H), PEA(C), PEA(O)—are presented. The electrical conductivity of the PEA(H)/PPY, PEA(C)/PPY, and PEA(O)/PPY composites are the same order of magnitude as PPY. The mechanical properties of the composite films are much better than that of pure PPY, and the composite films have good conductivity and thermostability. © 1994 John Wiley & Sons, Inc.
Thermochemical stress crazing and cracking of thermoplastics
Authors: Legrand D. G. 
Published: April 2003

AbstractA new method of inducing crazing and cracking in thermoplastics is discussed. The method involves the thermal quenching of hot thermoplastics into simple organic liquids or organic solutions. Data are presented for several different thermoplastics and a number of different liquids. The results are interpreted in terms of a model based on the work of Manning and Lineback that incorporates thermal strains and stresses, thermal conductivity, specific interfacial energies, and defects. The specific crazing energy for bisphenol‐A polycarbonate when quenched into isopropyl alcohol is determined to be approximately 3 × 105 erg/cm2 from this model. © 1994 John Wiley & Sons, Inc.
Modification of nylon‐6 with semi‐rigid poly(p‐diphenylmethyl terephthalamide) using MDI as a chain extender
Authors: Lin Ming‐Fung , Shu Yao‐Chi 
Published: April 2003

AbstractThe purpose of this study is to reinforce the flexible nylon‐6 by using Poly(p‐diphenylmethyl terephthalamide) (PMA) using MDI as a chain extender. Observation by scanning election microscopy showed that the multiblock copolymer had a homogeneous texture. From the differential scanning calorimetry measurements, the multiblock copolymers were shown to have only one melting point, Tm, which is higher than that of nylon‐6. The wide‐angle X‐ray diffraction pattern shows that nylon‐6 has two diffraction peaks at 2θ = 20° and 23.8°. However, the multiblock copolymer has only one peak at 2θ = 20°, indicating a different crystal structure of multiblock copolymers. The copolymers appears to have a significant reinforcing effect on the mechanical properties. © 1994 John Wiley & Sons, Inc.
Molecular model for solid‐state polymerization of nylon 6. II. An improved model
Authors: Kulkarni Mukund R. , Gupta Santosh K. 
Published: April 2003

AbstractAn improved mathematical model using the Vrentas–Duda theory for diffusion coefficients is developed for solid‐state polymerization (SSP). This model is applied to nylon 6, and best‐fit values of the parameters are obtained for this system using the Box complex analysis on available experimental data. The sensitivity of results to variations of these parameters is studied. It is found that the ring opening reaction can easily be omitted and the number of parameters thereby decreased. Detailed quantitative results are obtained to study the effects of changing the important operating conditions on SSP, e.g., intermediate remelting of nylon 6 powder, value of the water concentration (or level of vacuum) in the vapor phase, leaching of monomer and water before SSP, size and degree of crystallinity of polymer particles, etc. The diffusional effects on the rate constants are found to depend on a complex interplay of several important factors such as the generation of monomer and water by reaction, removal of water by macro‐level diffusion, changes in the intrinsic rate constants due to decrease in the concentration of polymer molecules, etc. © 1994 John Wiley & Sons, Inc.
Complexation between poly(2‐hydroxypropyl methacrylate) and three tertiary amide polymers
Authors: Dai Jie , Goh S. H. , Lee S. Y. , Slow K. S. 
Published: April 2003

AbstractThe complexation behavior between poly(2‐hydroxypropyl methacrylate) (PHPMA) and three isomeric tertiary amide polymers, namely, poly(N‐methyl‐N‐vinylacetamide) (PMVAc), poly(N,N‐dimethylacrylamide) (PDMA), and poly(2‐ethyl‐2‐oxazoline) (PEOx), was studied. PHPMA forms interpolymer complexes with the three tertiary amide polymers at the entire feed composition range in methyl ethyl ketone and tetrahydrofuran solutions, indicating a strong intermolecular interaction between different polymer chains. However, complexation does not occur between PHPMA and the three tertiary amide polymers in N,N‐dimethylformamide solutions. Infrared spectroscopic studies show that the intermolecular hydrogen bonding association between the hydroxyl groups in PHPMA and the amide carbonyl groups in the tertiary amide polymers is stronger than the self‐association between the hydroxyl groups and the ester carbonyl groups in PHPMA. PHPMA has a stronger complexation ability with these tertiary amide polymers than poly(styrene‐co‐allyl alcohol) and poly(hydroxyether of bisphenol‐A) do. © 1994 John Wiley & Sons, Inc.
Polymeric phosphonium salts as a novel class of cationic biocides. VIII. Synergistic effect on antibacterial activity of polymeric phosphonium and ammonium salts
Authors: Kanazawa Akihiko , Ikeda Tomiki , Endo Takeshi 
Published: April 2003

AbstractTwo types of homopolymers {poly[tributyl(4‐vinylbenzyl)phosphonium chloride] and poly[tributyl(4‐vinylbenzyl)ammonium chloride]} and copolymers, in which the compositional ratio of the phosphonium monomer to the ammonium monomer was altered, were prepared. The antibacterial activities of both the mixtures of the homopolymers in which the mixing ratio was altered and the copolymers containing positively charged phosphorus and nitrogen atoms in a single polymer chain were explored by the viable cell counting method in sterile distilled water. In the mixed system, a significant finding was the presence of an optimal mixing ratio for the antibacterial activity. The mixtures of polymeric phosphonium salt and polymeric ammonium salt clearly showed the synergistic effect on the antibacterial activity. On the other hand, the antibacterial activity of the copolymers with different cationic parts increased monotonously with increasing the phosphonium monomer units in the polymers, namely, the incorporation of two types of active moieties into a single molecule seems to be unfavorable for synergism on the antibacterial activity. © 1994 John Wiley & Sons, Inc.
Preparation and adsorption properties of the chelating fibers containing amino groups
Authors: Lu Yun , Wu Cuixia , Lin Weiping , Tang Liyuan , Zeng Hanmin 
Published: April 2003

AbstractFour kinds of amino‐group‐containing chelating fibers were prepared by reacting diethylenetriamine, diethanolamine, diethylamine, and aminopyridine, respectively, with a grafted fiber PVA‐g‐GMA containing epoxy groups. The γ‐ray preirradiation initiated graft copolymerization of GMA onto PVA fiber, the functionalization of the grafted fiber PVA‐g‐GMA with amino compounds, and the adsorption properties of the obtained chelating fibers were systematically investigated. It is concluded that with increasing monomer concentration, reaction time, and temperature, the grafting percentage increases significantly. In the functionalization of the grafted fiber, reaction time, temperature, solvent, and amount of amine used greatly influence the reaction. 1,4‐Dioxane is a reasonable solvent for the reaction. The chelating fibers present great adsorption amounts and high adsorption rates for Cu2+ ion and Au3+ ion. Among the chelating fibers, the fiber with diethylenetriamine group is the most reasonable chelating fiber for the adsorption of Cu2+ and Au3+. The chelating fibers present good selectivities for Cu2+ in the solution with Cu2+, Mn2+, Ni2+, Co2+, and Zn2+, while presenting quite high selectivities for Au3+ ion in the solution with Cu2+, Au3+, Zn2+, and Cr3+ ions. The chelating fiber with diethanolamine or diethylamine can reduce the adsorbed Au3+ into metallic gold. © 1994 John Wiley & Sons, Inc.
Epoxy/poly(methyl methacrylate) interpenetrating polymer networks—morphology, mechanical and thermal properties
Authors: Das B. , Chakraborty D. , Hajra A. K. , Sinha S. 
Published: April 2003

AbstractFull and semi‐IPNs were prepared from epoxy and poly methyl methacrylate (PMMA), by the sequential mode of synthesis and were characterized by measurements of ultimate tensile strength (UTS), elongation at break, modulus, and toughness. Aromatic polyamine adducts and ethylene glycol dimethacrylate were used as the crosslinkers for epoxy and comonomer/crosslinker for methyl methacrylate monomer, respectively. Higher UTS and modulus of the semi‐IPNs over full IPNs were attributed to the higher probability of interpenetration. The weight retention in the thermal decomposition of the IPNs and semi‐IPNs were higher than the epoxy homopolymer. This enhancement was presumably related to the presence of the unzipped methyl methacrylate monomer which acted as radical scavangers in the epoxy degradation. © 1994 John Wiley & Sons, Inc.
Sequence determination of vinyl acetate–methyl acrylate copolymers by NMR spectroscopy
Authors: Brar A. S. , Charan Shiv 
Published: April 2003

AbstractVinyl acetate/methyl acrylate (V/M) copolymers were prepared by free‐radical solution polymerization in benzene. Copolymer compositions were obtained from 1H‐NMR spectroscopy. Reactivity ratios for the copolymerization of V with M were calculated using the Kelen‐Tudos (KT) and the nonlinear error in variables (EVM) methods. The reactivity ratios obtained from the KT and EV methods are rV = 0.04 ± 0.03 and rM = 7.28 ± 2.88 and rv = 0.04 ± 0.01 and rM = 7.28 ± 0.37, respectively. The microstructure was obtained in terms of the distribution of V‐ and M‐centered triad sequences from 13C{1H}‐NMR spectra of copolymers. Homonuclear 1H‐2D‐COSY and 2D‐NOESY NMR were used to determine the most probable conformer for the V/M copolymer. The copolymerization behavior of the V/M copolymers as a function of conversion is also reported. © 1994 John Wiley & Sons, Inc.
Reactive diluent effect on properties of UV‐cured films
Authors: Ali K. M. Idriss , Khan Mubarak A. , Zaman M. M. , Hossain M. A. 
Published: April 2003

AbstractPolymer films were prepared with UV radiation from urethane acrylate oligomer (LR 8739) mixed with a photoinitiator (Irgacur 184) and a number of reactive diluents chosen from monofunctional monomers (such as N‐vinyl pyrrolidone, ethylhexyl acrylate, methoxyethyl acrylate, and hydroxyethyl methacrylate), difunctional monomers (hexane dioldiacrylate, butanediol diacrylate, and tripropylene diacrylate), and a trifunctional monomer (trimethylol propane triacrylate). The optimum concentrations of the photoinitiator, oligomer, and diluents were determined. Various properties of the cured films such as pendulum hardness, gel content, swelling ability, tensile strength, and elongation at break were also determined. The glass transition temperatures (Tg) of the diluents were correlated with tensile properties and those of the film. © 1994 John Wiley & Sons, Inc.
Integrally skinned polysulfone hollow fiber membranes for pervaporation
Authors: Koops G. H. , Nolten J. A. M. , Mulder M. H. V. , Smolders C. A. 
Published: April 2003

AbstractFrom polysulfone as polymer, integrally skinned hollow fiber membranes with a defect‐free top layer have been spun. The spinning process described here differs from the traditional dry‐wet spinning process where the fiber enters the coagulation bath after passing a certain air gap. In the present process, a specially designed tripple orifice spinneret has been used that allows spinning without contact with the air. This spinneret makes it possible to use two different nonsolvents subsequently. During the contact time with the first nonsolvent, the polymer concentration in the top layer is enhanced, after which the second coagulation bath causes further phase separation and solidification of the ultimate hollow fiber membrane. Top layers of ± 1 μm have been obtained, supported by a porous sublayer. The effect of spinning parameters that might influence the membrane structure and, therefore, the membrane properties, are studied by scanning electron microscopy and pervaporation experiments, using a mixture of 80 wt % acetic acid and 20 wt % water at a temperature of 70°C. Higher fluxes as a result of a lower resistance in the substructure could be obtained by adding glycerol to the spinning dope, by decreasing the polymer concentration, and by adding a certain amount of solvent to the bore liquid. Other parameters studied are the type of the solvent in the spinning dope and the type of the first nonsolvent. © 1994 John Wiley & Sons, Inc.
Selective crosslinking in polymer blends. I. Novel selective crosslink systems for polypropylene/unsaturated elastomer blends
Authors: Inoue Toshio 
Published: April 2003

AbstractTwo novel systems were developed to selectively crosslink dispersed unsaturated elastomer particles in saturated polyolefin matrices under dynamic crosslinking conditions. One system comprises N,N′‐m‐phenylene‐bis‐maleimide (PM) as a crosslinker and 6‐ethoxy‐2,2,4‐tri‐methyl‐1,2‐dihydroquinoline or polymerized‐ (2,2,4‐trimethyl‐1,2‐dihydroquinoline) as an activator. They are believed to form charge‐transfer‐complexes to produce PM radicals, which accelerate the crosslinking reaction of the elastomer. The other comprises PM as a crosslinker and 9,10‐dihydrophenanthrene as an activator. These are believed to act as a hydrogen acceptor and a hydrogen donor, respectively, involving transference of a hydrogen radical between them to produce a PM radical. These crosslink systems convert the unsaturated elastomer particles in the polyolefin matrices to crosslinked particles selectively without causing degradation or crosslinking of the matrices, because the radicals produced from the systems are carbon radicals and abstract only hydrogen radicals at the allylic positions of the unsaturated elastomers and not a hydrogen radical at the secondary or tertiary carbons of the polyolefin. The reactions and their confirmed selectivity were conducted on PP/EPDM blend, PP/SBS blend, PP/SIS blend, PP/1,2‐PB(1,2‐polybutadiene) blend, and PP/PE/EPDM blend, respectively. © 1994 John Wiley & Sons, Inc.
Graft copolymerization of acrylonitrile and methacrylonitrile onto gelatin by mutual irradiation method
Authors: Kaur Inderjeet , Barsola Raghuvir , Gupta Anita , Misra B. N. 
Published: April 2003

AbstractIn order to improve upon certain properties of gelatin graft copolymerization of acrylonitrile (AN) and methacrylonitrile (MAN) onto gelatin has been studied in aqueous medium using γ rays as a source of initiation. Optimum conditions for affording maximum percentage of grafting have been evaluated as a function of various reaction parameters. The grafted polyacrylonitrile (PAN) was isolated from the graft copolymer by acid hydrolysis, and the average molecular weight (Mv) of the isolated polymer has been determined viscometrically. The graft copolymers were characterized by IR spectroscopic methods and thermogravimetric analysis (TGA). Acrylonitrile was found to be more reactive than methacrylonitrile toward graft copolymerization. © 1994 John Wiley & Sons, Inc.
Vibrational spectra of some diisocyanates in the liquid state or on EPDM‐40 rubber surface
Authors: Kondyurin Alexey , Klyachkin Yuri 
Published: April 2003

AbstractIR transmission and Raman spectra of toluylene diisocyanate and hexamethylene diisocyanate and IR spectra of diphenylmethane diisocyanate, partially polymerized diphenylmethane diisocyanate, and polyisocyanurate were obtained. Toluylene diisocyanate and partially polymerized diphenylmethane diisocyanate form associates in the liquid state, which leads to anomalous intensity changes and a frequency shift to the νas (NCO) band in the spectrum of the treated rubber surface with time. The associate formation influences positively the properties of diisocyanates as rubber‐surface modifiers for adhesion. © 1994 John Wiley & Sons, Inc.
Synthesis and properties of unsaturated polyester diol–polyurethane hybrid polymer network
Authors: Xu Mei Xuan , Xiao Jing Song , Zhang Wen Hua , Yao Kang De 
Published: April 2003

AbstractThis article deals with the synthesis and properties of poly[(propylene glycol maleate)‐co‐(propylene glycol phthalate)] diol (PGMPD)/polyester–urethane or polyether–urethane hybrid polymer networks (HPNs). The polyurethane type and the molar ratio of NCO/OH have an effect on their properties. The structure–property relationship is discussed as well. © 1994 John Wiley & Sons, Inc.
Mechanical properties of LDPE/granular starch composites
Authors: Willett J. L. 
Published: April 2003

AbstractThe mechanical properties of composites of granular starch and low density polyethylene (PE) have been studied as functions of starch volume fraction ϕ, granule size, and presence of compatibilizer. Property–volume fraction relationships were interpreted using various theories of composite properties. The dependence of elongation (ϵ ∼ ϕ1/3) and tensile strength (σ ∼ ϕ2/3) agree with theoretical predictions, although the proportionality constants are less negative than theoretical values. The addition of compatibilzer (ethylene‐co‐acrylic acid copolymer, EAA) did not significantly affect the elongation or tensile strength, but significantly increased the composite tensile modulus. The cornstarch/PE moduli could be described by the Kerner or Halpin‐Tsai equations. Analysis of the composite moduli data using the Halpin‐Tsai equation allowed the estimation of the modulus of granular starch. The value obtained, 15 GPa, is considerably greater than most unfilled synthetic polymers of commercial importance, but significantly lower than the modulus of cellulose. It is also greater than a previously reported value of 2.7 GPa. © 1994 John Wiley & Sons, Inc.
Interaction of nylon 6‐clay surface and mechanical properties of nylon 6‐clay hybrid
Authors: Usuki Arimitsu , Koiwai Akihiko , Kojima Yoshitsugu , Kawasumi Masaya , Okada Akane , Kurauchi Toshio , Kamigaito Osami 
Published: April 2003

AbstractWe synthesized nylon 6‐clay hybrid materials using four types of clay minerals, montmorillonite, saponite, hectrite, and synthetic mica. The mechanical properties of their injection molded specimens were measured according to ASTM. Nylon 6‐clay hybrid using montmorillonite was superior to the other hybrids in mechanical properties. This might result from the difference in the interaction between nylon molecules and silicates in the hybrids. To clarify this hypothesis, we synthesized intercalated compounds of the clay minerals with glycine as the model of the hybrids, and analyzed the interaction using 15N cross polarization magic angle spinning (CP/MAS) NMR spectroscopy. The 15N‐NMR result reveals that the positive charge density on the nitrogen of the intercalated compound based on montmorillonite was largest in all the intercalated compounds. It was suggested that montmorillonite interacted strongly with nylon 6 by ionic interaction. This ionic interaction was one of the reasons why these hybrid materials had superior mechanical properties. © 1995 John Wiley & Sons, Inc.
Microstructural evolution of a silicon oxide phase in a perfluorosulfonic acid ionomer by an in situ sol–gel reaction
Authors: Mauritz K. A. , Stefanithis I. D. , Davis S. V. , Scheetz R. W. , Pope R. K. , Wilkes Garth L. , Huang Hao‐Hsin 
Published: April 2003

AbstractNanocomposites were produced via sol–gel reactions for tetraethylorthosilicate within the cluster morphology of perfluorosulfonic acid films. Small‐angle x‐ray scattering revealed that the polar/nonpolar nanophase‐separated morphological template persists despite invasion by the silicon oxide phase. Scanning electron microscopy (ESEM–EDAX) studies have indicated that the greatest silicon oxide concentration occurs near the surface and decreases to a minimum in the middle. Optical and ESEM micrographs revealed a brittle, surface‐attached silica layer at high silicon oxide contents. © 1995 John Wiley & Sons, Inc.
A study of the rate of formation of polysulfides of tetramethylthiuram disulfide
Authors: Geyser M. , McGill W. J. 
Published: April 2003

AbstractThe rate of formation of tetramethylthiuram polysulfides (TMTP), that play an important role in vulcanization, was studied. After a short induction period (<30 s), tetramethylthiuram disulfide (TMTD) and TMTD‐sulfur mixes, heated to 130–150°C in the absence of rubber, rapidly form a series of TMTPs. The concentrations of TMTPs of lower sulfur rank increase most rapidly, indicating that sulfur atoms are added to the accelerator sequentially. The incorporation of sulfur molecules to give TMTPs, which subsequently desulfurate, does not occur. Equilibrium concentrations of the various TMTPs are achieved in about 2 min. Little tetramethylthiourea is formed below 200°C. Tetramethylthiuram monosulfide (TMTM) is stable, but TMTM‐sulfur mixes form TMTPs. A mechanism is proposed to account for the large amount of TMTM formed on heating TMTD in the absence of sulfur and the correspondingly higher TMTP concentrations in the presence of sulfur. © 1995 John Wiley Sons, Inc.
Physical properties and dyeability of NaOH‐treated silk fibers
Authors: Freddi Giuliano , Kato Hiroshi , Tsukada Masuhiro , Allara Giulia , Shiozaki Hideki 
Published: April 2003

AbstractDomestic (Bombyx mori) and wild (tussah, Antheraea pernyi) silk fabrics were treated with diluted NaOH solutions by the pad/batch method. The equillbrium moisture regain of tussah silk fibers increased steadily with alkaline treatment, while that of B. mori did not change. B. mori tensile strenght and elongation at break were slightly impaired. The average molecular orientation and crystallinity of both kinds of silk remained unchanged. Differential scanning calorimetry (DSC) and thermomechanical analysis(TMA) showed that the thermal behavior of B. mori silk was almost unaffected, while that of tussah exhibited slight changes in the temperature range 250–300°C. By dynamic mechanical measurements (DMA) it was elucidated that both storage and loss moduli of B. mori silk fibers decreased following NaOH treatment. On the other hand, tussah silk exhibited a noticeable upward shift of the major loss peak. Alkali‐treated tussah silk fibers, dyed with an acid dyestuff, attained a lower degree of dye‐bath exhaustion. © 1995 John Wiley & Sons, Inc.