bluuebunny/crossref_metadata_2025_split huggingface dataset:
Lack of an association between 5‐HT1A receptor gene structural polymorphisms and suicide victims
Authors: Nishiguchi Naoki , Shirakawa Osamu , Ono Hisae , Nishimura Akiyoshi , Nushida Hideyuki , Ueno Yasuhiro , Maeda Kiyoshi 
Published: August 2002

AbstractA serotonergic dysfunction in the brain has been reported to be involved in suicidal behavior independently of the presence of a specific psychiatric disorder. Serotonin 1A (5‐HT1A) receptors are known to be located on serotonergic nerve terminals and to be involved in the presynaptic regulation of serotonin release. Genetic factors partly explain the risks for suicide, and a suicide completion group is thought to be more uniform than a suicide attempt group. To explore the hypothesis that the 5‐HT1A receptor‐induced serotonergic dysfunction is implicated genetically in suicide, we focused on the structural polymorphisms, Pro16Leu and Gly272Asp, of the 5‐HT1A receptor gene, and examined the association between suicide victims who completed suicide and these two polymorphisms. In both polymorphisms, we found no significant difference in genotype distribution or allele frequencies between suicide victims and controls. These findings suggest that neither of these two polymorphisms is associated with suicide victims and it is unlikely that the 5‐HT1A receptor gene is implicated in the susceptibility to suicide. © 2002 Wiley‐Liss, Inc.
Determination of methyltin species in sediments using a pervaporation–gas chromatographic approach
Authors: Gómez‐Ariza J. L. , Mingorance F. , Velasco‐Arjona A. , Giráldez I. , Sánchez‐Rodas D. , Morales E. 
Published: August 2002

AbstractA method for speciation of monomethyltin (MMT), dimethyltin (DMT) and trimethyltin (TMT) in sediments based on the coupling between a pervaporation module, a preconcentration system and a gas chromatograph coupled with a pulsed flame photometric detector is reported. All the species are derivatized using sodium tetraethylborate as an appropriate reagent in order to produce volatile compounds. The experimental approach consists of a high‐pressure injection valve. In one of the valve positions, the volatile tin species are driven to an appropriate minicolumn as a sorptive trap placed at the valve loop to preconcentrate the analytes. After a fixed time, the current valve position is changed for the injection mode and desorption of the preconcentrated analytes are obtained by heating in a furnace. Estimated detection limits (of tin) for MMT, DMT and TMT using 500 mg of sample are in all cases lower than 21 ng g−1. Excellent recoveries (between 90 and 98%) for tin species were obtained by this extremely simple and easily automated setup. Copyright © 2002 John Wiley & Sons, Ltd.
Studies of phosphonate‐containing bismaleimide resins. I. Synthesis and characteristics of model compounds and polyaspartimides
Authors: Shu Wei‐Jye , Perng Li‐Hsiang , Chin Wei‐Kuo 
Published: August 2002

AbstractTwo phosphonate‐containing bismaleimide (BMI) [(4,4′‐bismaleimidophenyl)phosphonate] monomers with different melting temperatures and similar curing temperatures were synthesized by reacting N‐hydroxyphenylmaleimide with two kinds of dichloride‐terminated phosphonic monomers. The BMI monomers synthesized were identified with 1H‐, 13C‐, and 31P‐nuclear magnetic resonance (NMR) spectroscopy and elemental analysis. The phosphonate‐containing BMI monomers react with a free‐radical initiator to prepare phosphonate‐containing BMI polymers and also with various aromatic diamines to prepare a series of polyaspartimides as reactive flame retardants. The polymerization degrees of polyaspartimides depend on the alkalinity and nucleophility of diamines as chain extenders. Differential scanning calorimetry (DSC) and thermogravimetry analysis (TGA) were used to study the thermal properties of the phosphonate‐containing BMI resins such as the melting temperature, curing temperature, glass transition temperature (Tg), and thermal resistance. All the phosphonate‐containing BMI resins, except the BMI polymers, have a Tg in the range of 210–256°C and show 5% weight loss temperatures (T5%) of 329–434 and 310–388°C in air and nitrogen atmospheres, respectively. The higher heat resistance of cured BMI resin relative to the BMI polymer is due to its higher crosslinking density. Since the recrosslinking reactions of BMI polymers and polyaspartimides occur more easily in an oxidation environment, their thermal stabilities in air are higher than are those in nitrogen gas. In addition, the thermal decomposition properties of polyaspartimides depend on the structures and compositions of both the diamine segments and the BMI segments. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1919–1933, 2002
Thermal and mechanical properties of fiber‐forming poly(urethane semicarbazide)s
Authors: Palanisamy Aruna , Ummadisetty Venkateshwarlu , Radhakrishan Ganga 
Published: August 2002

AbstractFiber‐forming poly(urethane semicarbazide)s were prepared with poly(butylene adipate)glycol as soft‐segment domains and hexamethylene diisocyanate/terephthalic dihydrazide as hard‐segment domains. The hard‐segment content was varied via variations in the polyol/isocyanate molar ratio, and the films were characterized by Fourier transform infrared spectroscopy and thermogravimetric analysis. The effect of the hard‐segment‐content variation on the properties was studied by differential scanning calorimetry, stress–strain analysis, and dynamic mechanical testing. Differential scanning calorimetry showed that the samples exhibited a very low level of hard/soft‐segment phase mixing. The stress–strain analyses revealed that the elongation at break decreased with an increase in the hard‐segment content and that the mechanical property depended on the overall crystallinity of the samples. Dynamic mechanical tests revealed a high glassy‐to‐rubbery state modulus and a high degree of phase separation between the hard and soft segments. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 86–93, 2002
Synthesis, characterization, and photochromic properties of PMMA functionalized with 4,4′‐diacryloyloxyazobenzene
Authors: Hu Xiao , Zhao Xiongyan , Gan Leong Huat , Xia Xulin 
Published: August 2002

AbstractAttempts to introduce the azo chromophore into poly(methyl methacrylate) (PMMA) molecular chains were made in search for a new approach to obtain functionalized‐PMMA (f‐PMMA) with high glass transition temperature and an adequate azo content. A novel functionalized monomer, 4,4′‐diacryloyloxyazobenzene (DAOAB), was synthesized and used as grafting agent in the polymerization of methyl methacrylate. 1H‐NMR spectrum, FTIR spectrum, elemental analysis, and MDSC measurement confirmed that the proposed structure of DAOAB was synthesized successfully. Furthermore, the thermal properties and photochromic behavior of f‐PMMA samples were also analyzed by DSC, TGA, and UV–visible spectroscopy. The results have shown that f‐PMMA exhibited a better photochromic behavior and considerably improved thermal properties than pure PMMA. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1061–1068, 2002
Effects of sulfonated surfactants on parallel diffusion of mono azo dye with high aggregation constant into cellulose membranes
Authors: Maekawa Masako , Kamada Chiyo , Miyata Kiyomi 
Published: August 2002

AbstractThe effects of sulfonated surfactants on the adsorption and diffusion of mono azo dye into water‐swollen cellulose membranes were studied at 25–55°C. The results were analyzed on the basis of the parallel diffusion theory of surface and pore diffusion. Addition of the surfactants increased the equilibrium adsorption of the dye onto cellulose and the pore diffusivity for the parallel diffusion model. The surface diffusivity for the model was not affected. The temperature dependence of the effects was also discussed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1781–1785, 2002
Preparation of porous poly(oxymethylene) membrane with high durability against solvents by a thermally induced phase‐separation method
Authors: Matsuyama Hideto , Kakemizu Masaki , Maki Taisuke , Tearamoto Masaaki , Mishima Kenji , Matsuyama Kiyoshi 
Published: August 2002

AbstractPorous poly(oxymethylene) membranes were prepared as new solvent‐resistant membranes by a thermally induced phase‐separation method. Porous structures were formed by solid–liquid phase separation (polymer crystallization) rather than liquid–liquid phase separation. The pores existed in the intraspherulitic and interspherulitic regions. The effects of the polymer weight percentage and cooling rate on toluene permeance and solute rejection were investigated. The solvent resistance of the membranes was tested by the immersion of the membranes in organic solvents for 1 month, and high durability against the solvents was confirmed. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 1993–1999, 2002
Effect of drying conditions on microwave conductivity of polyaniline
Authors: John Honey , Biju Kumar S. , Mathew K. T. , Joseph Rani 
Published: August 2002

AbstractPolyaniline was synthesized by using ammonium persulfate initiator in the presence of 1M HCl. It was dried under different drying conditions like room temperature drying (for 48 h), oven drying (at 50–60°C for 8 h under a vacuum), and vacuum drying (at room temperature for 16 h). The conductivities of these samples were measured at microwave frequencies. These samples were also pelletized and the measurements were repeated. The cavity perturbation technique was used for the study. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2008–2012, 2002
Compatibilization of side‐chain, thermotropic, liquid‐crystalline ionomers to blends of polyamide‐1010 and polypropylene
Authors: Li Yuanming , Zhang Bao Yan , Feng Zhiliu , Zhang Ailing 
Published: August 2002

AbstractA novel side‐chain, liquid‐crystalline ionomer (SLCI) with a poly(methyl hydrosiloxane) main chain and side chains containing sulfonic acid groups was used in blends of polyamide‐1010 (PA1010) and polypropylene (PP) as a compatibilizer. The morphological structure, thermal behavior, and liquid‐crystalline properties of the blends were investigated by Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis, and scanning electron microscopy. The morphological structure of the interface of the blends containing SLCI was improved with respect to the blend without SLCI. The compatibilization effect of greater than 8 wt % SLCI for the two phases, PA1010 and PP, was better than the effects of other SLCI contents in the blends. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2749–2754, 2002; DOI 10.1002/app.10179
Use of crosslinked poly(ferric acrylate) as a sorbent in solid‐phase extraction
Authors: Sreenivasan K. 
Published: August 2002

AbstractA sample‐preparation step, before chromatographic analysis, is frequently performed to enrich the components of interest from a complex matrix. This step is also needed to purify and concentrate the analyte present in a highly dilute medium. Solid‐phase extraction (SPE) with a specific sorbent is one of the most widely used techniques for extracting trace components from aqueous or nonaqueous media. In this method, analytes are extracted by the passage of the medium through a cartridge containing a solid matrix. The recovery of the analytes from the medium considerably depends on the extent of the interactions between the analytes and the sorbent. Through the enhancement of these interactions, the extent of the uptake of the analytes can be improved. Poly(acrylic acid) is commonly employed as the sorbent in SPE for the isolation of polar analytes. This article discusses the use of the metal‐containing polymer poly(ferric acrylate) as the sorbent for the isolation of a few phenols as representative components from water. The results indicate that the metal‐containing polymer has an enhanced adsorption capacity in comparison with the capacity of the widely used sorbent poly(acrylic acid). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2184–2187, 2002
Measurement of residual stresses in injection‐molded polymer parts by time‐resolved fluorescence
Authors: Ikawa Taiji , Shiga Tohru , Okada Akane 
Published: August 2002

AbstractTime‐resolved fluorescence properties of 9‐methylanthracene (9MAn) dispersed in film of polyvinylchloride (PVC) containing carbon black were studied under tensile loadings. The fluorescence lifetime of 9MAn decreased from 5.70 to 5.55 ns, whereas the stresses acting on the films increased from 0 to 3 MPa. The change in fluorescence lifetimes of 9MAn during the stress relaxation process showed that the fluorescence lifetimes were correlated with the stresses, not with the strains. The results suggest that 9MAn is a useful probe for monitoring stresses acting on the matrix. With the use of the fluorescence properties of 9MAn, the residual tensile stresses on the skin‐layer of PVC injection‐molded test pieces were estimated. The estimated residual stresses were about ∼ 1 MPa. The residual stresses were relaxed to 0 MPa with annealing at 100°C. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2600–2603, 2002
The flocculation of kaolin by cationic polyacrylamides and the effect of cationic surfactant on this process
Authors: McCarron Alison M. , Crispo Sabrina , Smith‐Palmer Truis 
Published: August 2002

AbstractThe flocculation of kaolin suspended in a dilute salt solution was studied as a function of the addition of cationic surfactant and cationic polyacrylamide (CPAM) added separately, consecutively, or simultaneously. Cationic polyacrylamide caused flocculation by bridging when added in low concentrations, but at higher concentrations, charge neutralization became the dominant mechanism and the flocculation rate was highly dependent on the charge density of the polymer. Adsorption of sufficient polymer or surfactant (cetyl pyridinium chloride) prevented immediate adsorption of the other, although surfactant could replace polymer after extended agitation. The adsorption of polymer was greatest when small flocs were formed by charge neutralization or by prolonged shaking. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2382–2389, 2002
Synthesis and characterization of novel copolymers with the trimethylsilyl group for deep‐UV photoresists
Authors: Chiang Wen‐Yen , Lin Yung‐Ching 
Published: August 2002

AbstractN‐(4‐Acetoxyphenyl) maleimide (APMI) and three kinds of comonomers bearing a trimethylsilyl group were copolymerized at 60°C in the presence of azobisisobutyronitrile (AIBN) as an initiator in 1,4‐dioxane to obtain the three IP, IIP, and IIIP copolymers. These copolymers were removed from the acetoxy group in a transesterification process into new IVP, VP, and VIP copolymers with a pendant hydroxyl group. Two modified processes were adopted to prepare photoresists using these copolymers. The first process involved mixing the dissolution inhibitor, o‐nitrobenzyl cholate, with the new copolymers. Second, o‐nitrobenzyl cholate was introduced into the copolymers using 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) in dimethylformamide (DMF). The cyclic maleimide structure is responsible for the high thermal stability of these copolymers. After irradiation using deep–UV light and development with aqueous Na2CO3 (0.01 wt %), the developed patterns showed positive images and exhibited good adhesion to the silicon wafer without using any adhesion promoter. The resolution of these resists was at least 0.8 μm and an oxygen‐plasma etching rate was 1/5.3 to that of hard‐baked HPR‐204. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2791–2798, 2002; DOI 10.1002/app.10255
Thermally crosslinkable poly(phenylene sulfide)/poly(ether sulfone)/polymerization of monomer reactant–polyimide blends
Authors: Lai Mingfang , Yang Yuming , Liu Jingjiang 
Published: August 2002

AbstractThe effects of thermally crosslinkable polymerization of monomer reactant–polyimide (POI) on the miscibility, morphology, and crystallization of partially miscible poly(ether sulfone) (PES)/poly(phenylene sulfide) (PPS) blends were investigated with differential scanning calorimetry and scanning electron microscopy. The addition of POI led to a significant reduction in the size of PPS particles, and the interfacial tension between PPS and crosslinked POI was smaller than that between PES and crosslinked POI. During melt blending, crosslinking and grafting reactions of POI with PES and PPS homopolymers were detected; however, the reaction activity of POI with PPS was much higher than that with PES. The crosslinking and grafting reactions were developed further when blends were annealed at higher temperatures. Moreover, POI was an effective nucleation agent of the crystallization of PPS, but crosslinking and grafting hindered the crystallization of PPS. The final effect of POI on the crystallinity of the PPS phase was determined by competition between the two contradictory factors. The crosslinking and grafting reactions between the two components was controlled by the dosage of POI in the blends, the premixing sequence of POI with the two components, the annealing time, and the temperature. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2906–2914, 2002; DOI 10.1002/app.10287
Preparation of a self‐compatibility alloy via a seed‐graft concentrated‐emulsion pathway
Authors: Li Hangquan , Du Zhongjie , Huang Haohao 
Published: August 2002

AbstractA novel polymerization procedure, the concentrated‐emulsion graft polymerization of styrene monomer with poly(butyl acrylate) seed, was proposed for the production of a self‐compatibility macromolecule alloy. The effects of the butyl acrylate content, sodium dodecyl sulfate concentration, and polymerization temperature on the graft ratio were investigated. Scanning electron microscopy, transmission electron microscopy, and impact strength were used to characterize the microstructure and mechanical performance of the self‐compatibility macromolecule alloy. The results showed that increasing the butyl acrylate content, reducing the sodium dodecyl sulfate concentration, and improving the polymerization temperature all favored an increased graft ratio, which resulted in increased impact strength of the self‐compatibility macromolecule alloy. Therefore, the concentrated‐emulsion polymerization method is particularly suitable for seed‐graft polymerization. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2915–2920, 2002; DOI 10.1002/app.10288
Bulk modification of styrene–butadiene–styrene triblock copolymer with maleic anhydride
Authors: Wilhelm Helena Maria , Felisberti Maria Isabel 
Published: August 2002

AbstractThe bulk modification of SBS rubber with maleic anhydride in a mixing chamber of a Haake rheomixer was studied. The effect of temperature, maleic anhydride, and benzoyl peroxide concentrations on the grafting efficiency was evaluated. High grafting efficiency was achieved when the ratio of peroxide and maleic anhydride concentration was high. On the other hand, on this condition high insoluble fraction was generated. The addition of a diamine, 4,4′‐diaminediphenylmethane to the reaction mixture minimizes the amount of insoluble polymer. However, the grafted MAH content also decreases. The graft copolymer was characterized by infrared spectroscopy and the grafting extension was determined by titration. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 2953–2960, 2002; DOI 10.1002/app.10355
Epifluorescence studies and secondary relaxation processes in immiscible blends of polybutadiene‐poly(2‐vinyl naphthalene) by fluorescence spectroscopy
Authors: Cruz M. C. P. , Cassiola F. M. , Atvars T. D. Z. 
Published: August 2002

AbstractThe development of the morphology of polybutadiene/poly(2‐vinyl naphthalene) blends in five proportions by mass (5, 10, 50, 90, and 95%, w/w) is studied by epifluorescence and scanning electron microscopy (SEM) techniques. The phase separation process of these immiscible polymers produces a primary morphology that is formed by dispersed droplets in a continuous matrix. In the sequence a secondary phase separation inside the primary domains is detected by epifluorescence microscopy of the intrinsically fluorescent domains. Secondary phase separation is confirmed by SEM fracture surface analysis. The relative size of the droplets and the matrix composition depend on the proportion of the components of the blends. The mechanism of the phase separation process is preferentially by nucleation growth for either primary or secondary phase separation processes. Secondary relaxation processes involving the poly(2‐vinyl naphthalene) phase are studied by fluorescence spectroscopy. The profile of the steady‐state excimer fluorescence of poly(2‐vinyl naphthalene) with the temperature in the blend differs from that of the isolated homopolymer and is explained by the contribution from the interface to the radiationless deactivation. The Arrhenius plot for the temperature dependence exhibits slope changes that are related to the polymer relaxation processes. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1637–1649, 2002; DOI 10.1002/app.10389
Effect of partitioning of monomer on the reactivities of monomers in microemulsion
Authors: Sanghvi Paresh G. , Pokhriyal Naveen Kumar , Devi Surekha 
Published: August 2002

AbstractCopolymerization of styrene and 2‐hydroxyethyl methacrylate (2‐HEMA) was carried out in a microemulsion medium. The composition of the copolymers was estimated using proton 1H‐NMR. The reactivity ratios of styrene and 2‐HEMA in ternary microemulsions were observed and were considerable different from those reported for solution and bulk polymerization. In monomer pairs with a considerable difference in polarity, partitioning of a monomer between the aqueous phase and the microemulsion droplets develops a concentration gradient, which can be calculated from the distribution coefficient of the monomer between the two phases. This approach has led to more reliable reactivity ratios for the monomers. The study of styrene–2‐HEMA copolymerization in a sodium dodecylsulfate‐based microemulsion resulted in rS = 3.79 and rH = 0.17 as apparent reactivity ratios and rS = 0.57 and rH = 23.24 as true reactivity ratios for styrene and 2‐HEMA, respectively. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1832–1837, 2002; DOI 10.1002/app.10401