bluuebunny/crossref_metadata_2025_split huggingface dataset:
Historical Review. Of garlic, mice and Gmelin: the odor of trimethylarsine
Authors: Chasteen Thomas G. , Wiggli Markus , Bentley Ronald 
Published: August 2002

AbstractIn the 19th century, rooms were frequently decorated with wallpaper containing arsenical pigments; illness and fatalities often resulted. In 1839, Leopold Gmelin described a mouse‐like odor under those conditions. Much later, it was recognized that the problem was the formation of toxic and volatile trimethylarsine by fungal action. Gmelin's observation was misreported as a garlic‐like odor that is characteristic of trimethylarsine. Gmelin's original article in German and an English translation are included, and possible explanations for the incorrect reporting and for the original observation are described. Copyright © 2002 John Wiley & Sons, Ltd.
The synthesis, characterization and polycondensation of metal‐containing diols: crystal structure of [(η5‐C5H5)(CO)2Fe(CH2)3O‐{2,6‐(CH2OH)2‐4‐CH3C6H2}]
Authors: Mapolie S. F. , Mavunkal I. J. , Moss J. R. , Smith G. S. 
Published: August 2002

AbstractThe synthesis of two new transition‐metal‐containing polyesters is described. The precursors are bifunctional organometallic monomers that were synthesized using 2,6‐bis(hydroxymethyl)‐p‐cresol as the key reagent. This was achieved by simple coupling reactions between the appropriate organometallic alkyl halide and the cresol reagent. Polycondensation reactions were carried out with terephthaloyl chloride using ambient temperature solution techniques. The new low molecular weight oligomeric polyesters were characterized using Fourier transform infrared and 1HNMR spectroscopy, differential scanning calorimetry, thermogravimetric analysis and size‐exclusion chromatography analyses. Copyright © 2002 John Wiley & Sons, Ltd.
Gas transport properties of a series of cardo polyarylethers
Authors: Wang Zhonggang , Chen Tianlu , Xu Jiping 
Published: August 2002

AbstractGas transport of H2, CO2, O2, N2, and CH4in a series of cardo polyarylethers were examined over a temperature range of 30 ∼ 100°C. These polymers include three poly(aryletherketone)s, two poly(arylethersulfone)s, and one poly(aryletherketoneketone). It was found that the large length/diameter ratio of the polymer repeat unit for cardo polyaryletherketoneketone (PEKK‐C) and strong intermolecular interaction in hydrogen‐bonded polyarylethersulfone (PES‐H) and hydrogen‐bonded polyaryletherketone (PEK‐H) resulted in a considerable increase in gas permselectivity. Alkyl‐substituted polyaryletherketone (PEK‐A), bearing a pendant bulky propyl group on the cardo ring, simultaneously exhibited 62.5% higher H2permeability and 59.8% higher H2/N2permselectivity than unmodified poly(aryletherketone) (PEK‐C). The causes of the trend were interpreted in terms of chain packing density, segmental motion ability, steric factor, and intermolecular interaction of polymers, together with gas kinetic diameter and critical temperature data. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 791–801, 2002
Effects of crosslinking on thermal and mechanical properties of polyurethanes
Authors: Chiou Bor‐Sen , Schoen Paul E. 
Published: August 2002

AbstractThe effects of chemical crosslinking on the thermal and dynamic mechanical properties of a polyurethane system were examined. The polyurethanes were prepared from poly(propylene glycol), a diol; trimethylolpropane propoxylate, a triol; and poly(propylene glycol), tolylene 2,4‐diisocyanate terminated, a diisocyanate monomer. The crosslink density was controlled by varying the triol concentration from 10 to 70 mol % and the isocyanate‐to‐hydroxyl (NCO/OH) ratio from 1.0 to 1.3. All the samples had one glass‐transition temperature and no crystalline regions. In addition, there were larger increases in glass‐transition temperature over the range of triol concentrations studied than over the range of NCO/OH ratios studied. For all samples, the Dibenedetto equation relating glass‐transition temperature to extent of crosslinking fit the data very well. Also, samples with higher crosslink densities had much larger elastic moduli for temperatures above the glass‐transition temperature. By assuming the system was a phantom network, approximate crosslink densities for stoichiometric samples were obtained from the dynamic mechanical data and these agreed fairly well with theoretical predictions. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 212–223, 2002
Chain‐extended polyurethane–acrylate ionomer for UV‐curable waterborne coatings
Authors: Yang Jianwen , Wang Zhiming , Zeng Zhaohua , Chen Yonglie 
Published: August 2002

AbstractConventional and chain‐extended UV‐curable waterborne polyurethane–acrylate (PUA) ionomers were prepared from diisocyanate, polyethylene glycol (PEG), dimethylolpropionic acid, and hydroxyethyl methacrylate, and identified with FTIR spectra and 500‐MHz 1H‐NMR spectra. The number‐average molecular weight (Mn) and polydispersity of chain‐extended PUA were determined by gel permeation chromatography. For the synthesis of chain‐extended PUA, water was employed as the chain extender. The two kinds of PUA prepolymer could be easily dispersed in water in the form of self‐emulsified latex after the carboxyl group attaching to the backbone of PUA was neutralized with tertiary amine. The effects of Mn of PEG, carboxyl content, and type of diisocyanate on the interfacial tension and rheological behavior of PUA dispersions were investigated. The chain‐extended PUA prepolymer could photopolymerize to a greater extent than the conventional PUA, as indicated by differential photocalorimetry. The photopolymerization kinetics of chain‐extended PUA, based on different substrates, were also investigated. The differential scanning calorimetry analysis for the photo‐cured films from PUA dispersions suggested that lower Mn of PEG tended to favor phase mixing between soft and hard segment phases, and higher Mn of PEG would provoke phase separation. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1818–1831, 2002; DOI 10.1002/app.10384
The kinetics of the thermal decomposition of poly(3‐hydroxybutyrate) and maleated poly(3‐hydroxybutyrate)
Authors: Chen Cheng , Fei Bin , Peng Shuwen , Zhuang Yugang , Dong Lisong , Feng Zhiliu 
Published: August 2002

AbstractThe thermal decomposition mechanism of maleated poly(3‐hydroxybutyrate) (PHB) was investigated by FTIR and 1H NMR. The results of experiments showed that the random chain scission of maleated PHB obeyed the six‐membered ring ester decomposition process. The thermal decomposition behavior of PHB and maleated PHB with different graft degree were studied by thermogravimetry (TGA) using various heating‐up rates. The thermal stability of maleated PHB was evidently better than that of PHB. With increase in graft degree, the thermal decomposition temperature of maleated PHB gradually increased and then declined. Activation energy Ea as a kinetic parameter of thermal decomposition was estimated by the Flynn‐Wall‐Ozawa and Kissinger methods, respectively. It could be seen that approximately equal values of activation energy were obtained by both methods. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1789–1796, 2002; DOI 10.1002/app.10463
The development of controllable complex curing agents for epoxy resins. II. Examining the dissociation and thermal behavior of transition metal‐diamine complex‐epoxy blends
Authors: Hamerton Ian , Hay John N. , Herman Henryk , Howlin Brendan J. , Jepson Peter , Gillies Duncan G. 
Published: August 2002

AbstractA series of complexes incorporating diamine (o‐phenylene diamine and 2‐aminobenzylamine) ligands and containing the acetato and chloro salts of Ni(II) and Cu(II) was incorporated into two commercial epoxy resins recognized as industry standards (MY721 and MY750). The cure properties of the complexes are assessed alongside commercial curative systems. Thermal analysis (principally differential scanning calorimetry) shows that the nature of the cure mechanism can be dramatically affected by the nature of the transition metal and counterion (and the level of curing agent incorporation). For example, by using a nickel(II) acetato complex rather than its chloro analog, the onset of the cure reaction of MY721 may be reduced by 40 K. Thermogravimetric analysis, and visible, infrared, and electron spin resonance spectroscopy are employed to determine the point at which the complexes undergo dissociation. The data show that Cu(2‐ABA)2(ac)2 appear to dissociate at temperatures between 70 and 80°C in octan‐1‐ol. A multivariate approach is applied to the analysis of infrared data obtained for solvated complex samples subjected to a heating program and the results are consistent with the dissociation temperature obtained from the other spectral data. The data suggest that the aromatic amino function in the complex undergoes dissociation from the metal at a lower temperature than the aliphatic amine. The 2‐ABA‐based complexes containing chloride counterions undergo gelation at higher temperatures than their acetato analogs (for both commercial epoxy systems). The newly prepared complexes generally display ηmin values comparable with the commercial curative systems [the exceptions being Cu(2‐ABA)2Cl2 and Ni(OPD)3Cl2, which produce markedly higher values of 14 and 10 P, respectively], but it is believed that this is due to agglomeration and settling of the complex as the resin viscosity decreases during the heating cycle. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 2411–2424, 2002
Surface modification of low‐density polyethylene films by UV‐induced graft copolymerization with a fluorescent monomer
Authors: Wu J. Z. , Kang E. T. , Neoh K. G. , Wu P.‐L. , Liaw D. J. 
Published: August 2002

AbstractSurface modification of argon plasma–pretreated low‐density polyethylene (LDPE) film via UV‐induced graft copolymerization with a fluorescent monomer, (pyrenyl)methyl methacrylate (Py)MMA, was carried out. The chemical composition and morphology of the (Py)MMA‐graft‐copolymerized LDPE [(Py)MMA‐g‐LDPE] surfaces were characterized, respectively, by X‐ray photoelectron spectroscopy (XPS) and by atomic force microscopy (AFM). The concentration of the surface‐grafted (Py)MMA polymer increased with Ar plasma pretreatment time and UV graft copolymerization time. The photophysical properties of the (Py)MMA‐g‐LDPE surfaces were measured by fluorescence spectroscopy. After graft copolymerization with the fluorescent monomer, the surface of the LDPE film was found to have incorporated new and unique functionalities. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 1526–1534, 2001
Synthesis of nylon 6,6 copolymers with aromatic polyamide structure
Authors: Wang Huei‐Hsiung 
Published: August 2002

AbstractIn this article, flexible nylon 6,6 was reinforced with rigid‐chain aromatic polyamides based on poly(4,4′‐diphenylsulfone terephthalamide) (PSA), poly(p‐diphenyl oxide terephthalamide) (POA), poly(p‐diphenylmethane terephthalamide) (PMA), and isophthaloyl chloride (IPC). Various high molecular weight block copolyamides were synthesized by solution polymerization using p‐aminophenylacetic acid (p‐APA) as a coupling agent. Their thermal properties show that the block copolyamides exhibit higher values of Tg and Tm and better thermal stability than those of nylon 6,6, especially the IPC‐modified nylon 6,6. The order of increased thermal properties of copolyamides is IPC > POA > PMA > PSA. From wide‐angle X‐ray diffraction patterns, it was found that nylon 6,6 has two diffraction peaks, that is, 2θ = 20.5° and 23°, while the multiblock copolymers showed only one at 2θ = 20°, indicating a different crystal structure. It was found that the mechanical properties of the IPC‐modified nylon 6,6 were improved more than those of the semirigid copolyamides. The order of tensile strength was IPC > PSA > PMA > POA, but for elongation, it was POA > PMA > PSA > IPC. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 80: 2167–2175, 2001
Characterization and application of high magnetic property chitosan particles
Authors: An Xiaoning , Su Zhixing 
Published: August 2002

AbstractHigh magnetic property chitosan particles were prepared from chitosan coated on magnetic powder, glutaraldehyde modified, and then epichlorohydrin crosslinked. The magnetic properties, the surface, and the morphology of the magnetic particles were characterized. An optimum condition of immobilization of aprotinin on magnetic particles was obtained, then these particles were used for affinity purification of trypsin, and the condition of affinity purification was discussed. The proposed method was successfully applied to the purification of trypsin. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 1175–1181, 2001
A novel determination technique of polymer viscosity‐average molecular weights with flow piezoelectric quartz crystal viscosity sensing
Authors: Mao Youan , Wei Wanzhi , Zhang Jinzhong , Li Yijin 
Published: August 2002

AbstractA new method for the determination of polymer viscosity‐average molecular weights was developed with flow piezoelectric quartz crystal (PQC) viscosity sensing. The experimental setup with a 9 MHz AT‐cut quartz crystal and a flow detection cell was constructed and shown to be able to give highly reproducible data under the temperature of 25 ± 0.1°C and the fluid flow rate of 1.3–1.6 mL/min. A response model for PQC in contact with dilute polymer solutions (concentration <0.01 g/mL) was proposed in which the frequency change from the pure solvent, Δfs, follows Δfs = −k6ηl1/2 + k7, where ηl is the absolute viscosity of dilute polymer solution and k6 and k7 are the proportionality constants. This model was examined with poly(ethylene glycol) samples (PEG‐20000 and PEG‐10000) under the aforementioned experimental conditions using water as solvent. The result was Δfs = −1587ηl1/2 + 1443. Based on this model, the method for the determination of polymer viscosity‐average molecular weights, Mη, by flow PQC viscosity sensing was described and examined with an unknown poly(vinyl alcohol) (PVAL) sample. The new method proved to be an attractive and promising alternative for the determination of polymer molecular weights based on the good agreement between the molecular weight determined by the new method (Mη = 58600) for the unknown PVAL sample with that determined by the conventional capillary viscosity method. The new method has some advantages over the conventional viscosity method; for examples, operation is simpler and more rapid; the instruments required are cheaper and portable; the needed sample quantity is smaller; and the experimental setup constructed can be used in continuous measurement. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 63–69, 2001
High dielectric constant composites based on metallophthalocyanine oligomer and poly(vinylidene fluoride‐trifluoroethylene) copolymer
Authors: Xu Haisheng , Bai Yi , Bharti Vivek , Cheng Z.‐Y. 
Published: August 2002

AbstractUsing a solution casting method, a high dielectric constant composite based on a copper‐phthalocyanine (CuPc) oligomer and a poly(vinylidene fluoride‐trifluoroethylene) copolymer is developed. The experimental data show that the low field dielectric constant of the composites (with 55 wt % CuPc) can reach 1000 and the loss is ∼0.5 at room temperature and 100 Hz. Because of the long‐range electron delocalization in CuPc, which results in a strong space charge response of the composite to the external field, there is a strong frequency dispersion of the dielectric properties. In addition, the dielectric properties exhibit a nonlinear behavior with electric field. At a field of 10 kV/cm, the dielectric constant at 10 Hz reaches 4500; meanwhile the dielectric loss is also high. One of the unique attributes of the composite is its mechanical properties that remain very much the same as those of the polymer matrix. Even for a composite with 55 wt % CuPc (the volume fraction of CuPc in the composite is also in the similar range), the composite film is still flexible, with a Young's modulus of 1.2 GPa at room temperature. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 70–75, 2001
Caffeine selectivity of divinylbenzene crosslinked polymers in aqueous media
Authors: Villamena Frederick A. , De La Cruz Armah A. 
Published: August 2002

AbstractThe selective binding of caffeine to polymers is of interest in developing caffeine‐specific sensors. The influence of the nature and quantity of crosslinking agents and functional monomers on the selectivity and binding affinity of a polymer to caffeine is reported. A high binding affinity and selectivity of divinylbenzene (DVB) crosslinked polymers toward caffeine was exhibited by the binding competition of caffeine with several dimethylated and chlorinated xanthines and N‐methylated uric acids in aqueous media. To understand the nature of the caffeine–polymer interaction, we performed binding studies with solvents of different polarities and ionic strengths. The binding properties of DVB‐based polymers containing different functional monomers were compared with Amberlite® XAD resins. Analytes with hydrophilic and electron‐withdrawing groups lowered their binding affinity with the polymer in comparison with caffeine and its dimethylated derivatives. The caffeine–polymer interaction appeared to be predominantly a hydrophobic π–π interaction but partly due to the presence of caffeine‐specific sites. The reversibility of the caffeine–polymer binding was investigated, and the dissociation constants were approximated to be 27 and 6 mM. Dipole moments of caffeine and related molecules were estimated theoretically and were correlated with their corresponding B/T ratio, which is defined as the fraction of caffeine bound to the polymer. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 195–205, 2001
Mill processability of brominated isobutylene‐co‐paramethylstyrene and its blends with EPDM
Authors: Kumar Bhuwneesh , De P. P. , De S. K. , Bhowmick A. K. , Peiffer D. G. 
Published: August 2002

AbstractMilling behavior of brominated isobutylene‐co‐paramethylstyrene (BIMS) and its blends with ethylene propylene diene terpolymer (EPDM) rubber, was investigated over a range of temperatures and friction ratios in a drop mill operation. BIMS showed striking changes, that is, from a loose nervy band to a tight elastic band, as the temperature of the rolls was increased from 30°C to 90°C. For EPDM a loose band was observed at all temperatures and friction ratios studied. For the blends of BIMS and EPDM, the milling behavior changed from a tight elastic band to a loose bagging band on increasing the EPDM content. The critical nip gap (CNG), at which the front‐to‐back roll (F–B) transition occurred, was also measured. BIMS showed a much higher value of CNG than that of EPDM, indicating that the former had a significantly higher tendency for F–B transition than the latter material. For different blends of BIMS and EPDM, the CNG decreased on increasing the EPDM content, indicating a decrease in the tendency for F–B transition. The results were explained in terms of the rubber‐to‐metal adhesion and the viscosity of the polymers. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1483–1494, 2001
Polyimide surface modification by pulsed ultraviolet laser irradiation with low fluence
Authors: Lu Qing‐Hua , Li Mei , Yin Jie , Zhu Zi‐Kang , Wang Zong‐Guang 
Published: August 2002

AbstractSurface modification on a polyimide film by pulsed ultraviolet (UV) laser irradiation with a fluence below its ablation threshold was studied by X‐ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), and UV‐vis spectroscopy. It was observed that a photochemical reaction occurred and hydrophilic groups, such as —OH and —COOH, formed on the polyimide surface after irradiation. In addition, a ripple microstructure formed on the surface when the angle of incidence of the laser beam was 20–50o. The contact angle of the polyimide surface with water decreased and the adsorption ability of the surface to a water‐soluble dye clearly increased after laser irradiation. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 2739–2743, 2001
Effects of silicone oil and polymeric modifiers on the mechanical properties of highly filled LLDPE
Authors: Zhu Song , Zhang Yong , Zhang Yinxi 
Published: August 2002

AbstractThe effects of coupling agents, silicone oil, and three types of polymeric modifiers on the mechanical properties of linear low density polyethylene (LLDPE) composites highly filled with aluminium hydroxide [Al(OH)3] were studied. Polymeric modifiers that contain polar groups, such as silane‐grafted polyethylene (Si‐g‐PE) and acrylic‐acid‐grafted ethylene‐vinyl acetate copolymer (AA‐g‐EVA), improve the mechanical properties dramatically, while nonpolar modifiers improve them to some extent. When Al(OH)3 was treated using a titanate coupling agent, the silicone oil increased the impact strength and elongation at break of the LLDPE/Al(OH)3 composites. Introduction of a polymeric modifier containing polar groups destroys the beneficial effects of silicone oil on film mechanical properties, while the introduction of a nonpolar elastomeric polymeric modifier retains the high impact strength and elongation at break. SEM analyses provide the indirect evidence of the encapsulation of silicone oil around the filler. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 83: 121–128, 2002
Evidence for the recent extinction of two Arctic charr Salvelinus alpinus (L.) populations in the West of Ireland
Authors: Igoe F. , O'Grady M. , Byrne C. , Gargan P. , Roche W. , O'Neill J. 
Published: August 2002

Abstract1. This paper highlights the recent extinctions of two native Arctic charr populations in the West of Ireland, one population from the Lough Conn catchment, and a second from the Lough Corrib catchment, respectively.2. The distribution of charr populations in the two catchments is reviewed. The current distribution information is drawn from recent fish stock surveys (Lough Corrib in 1996, and Lough Conn in 1997 and 1998). Previous records of charr in the literature and unpublished data are described to place the current distribution of charr within these catchments into a historical perspective.3. The importance of the charr population in Lough Mask (Lough Corrib catchment) is emphasized, as it is one of the last extant examples of charr from a large Irish alkaline lake.4. Impacts on charr populations in both catchments are discussed and conservation measures proposed. Copyright © 2001 John Wiley & Sons, Ltd.