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  • Physics  (55)
  • Inorganic Chemistry  (28)
  • Occupational Health and Environmental Toxicology  (6)
  • Wiley-Blackwell  (89)
  • 1980-1984  (89)
  • 1940-1944
  • 1984  (89)
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  • Wiley-Blackwell  (89)
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  • 1980-1984  (89)
  • 1940-1944
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  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 1757-1773 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The placement of ionic groups within the molecular structure of a polymer produces marked modification in physical properties. A large number of studies have been performed on these ion-containing polymers, but few have focused on the effects of anion-cation interactions (i.e., counterion binding or ionization) on hydrodynamic volume, especially as the molecular structure of the solvent and nature of counterion are varied. In this study changes in hydrodynamic volume are followed through reduced viscosity measurements as a function of the abovementioned molecular parameters.The dilute solution properties of various polyelectrolytes that contain sulfonate and carboxylate groups were investigated as a function of the counterion structure, charge density, molecular weight, and solvent structure. The polymeric materials were selected because of their specific chemical structure and physical properties. In the first instance a (2-acrylamide-2 methylpropanesulfonic acid)-acrylamide-sodium vinyl sulfonate terpolymer was synthesized and subsequently neutralized with a series of bases. Viscometric measurements on these materials indicate that the nature of the cation affects the ability of the polyelectrolyte to expand its hydrodynamic volume at low polymer levels. The magnitude of the molecular expansion is shown to be due in part to the ability of the counterion to dissociate from the backbone chain, which, in turn, is directly related to the solvent structure. The changes in solution behaviour of these inomers lend support for the existence of ion pairs (i.e., site binding) and ionized moieties on the polymer chains. Measurements performed in a variety of solvent systems further confirm this interpretation. In addition, and acrylamide-sodium vinyl sulfonate copolymer was partially hydrolyzed with sodium hydroxide to study the effect of varying the charge density at a constant degree of polymerization and counterion structure. The results show that the charge density has a significant effect on the magnitude of the reduced viscosity and dilute solution behaviour. These observations, made in aqueous and nonaqueous solvents, are related to the interrelation of hydrodynamic volume, counterion concentration, and site binding. Again the controlling factor is the degree of site binding of the counterion onto the polymer backbone. Finally, we observe that the increased hydrodynamic volume affects viscosity behavior beyond the polyelectrolyte effect regime. If the average charge density on the macromolecule is relative high and/or the molecular weight is large (≥ 106) sufficient intermolecular interactions will occur to produce rapid changes in reduced viscosity.
    Additional Material: 11 Ill.
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  • 2
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Bioelectromagnetics 5 (1984), S. 101-112 
    ISSN: 0197-8462
    Keywords: 60-Hz electric fields ; rats ; behavior ; teratology ; growth ; Life and Medical Sciences ; Occupational Health and Environmental Toxicology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Physics
    Notes: A series of three experiments was performed to determine the effects of 30-day exposures to uniform 60-Hz electric fields (100 kV/m) on reproduction and on growth and development in the fetuses and offspring of rats. In the first experiment, exposure of females for 6 days prior to and during the mating period did not affect their reproductive performance, and continued exposure through 20 days of gestation (dg) did not affect the viability, size, or morphology of their fetuses. In the second experiment, exposure of the pregnant rat was begun on 0 dg and continued until the resulting offspring reached 8 days of age. In the third experiment, exposure began at 17 dg and continued through 25 days of postnatal life. In the second and third experiments, no statistically significant differences suggesting impairment of the growth or survival of exposed offspring were detected. In the second experiment, a significantly greater percentage of the exposed offspring showed movement, standing, and grooming at 14 days of age than among-sham-exposed offspring. There was a significant decrease at 14 days in the percentage of exposed offspring displaying the righting reflex in the second experiment and negative geotropism in the third experiment. These differences were all transient and were not found when the animals were tested again at 21 days of age. Evaluation of the reproductive integrity of the offspring of the second experiment did not disclose any deficits.
    Additional Material: 1 Ill.
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 22 (1984), S. 1011-1027 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A series of polypropylene-copolymer laminates produced by biaxial orientation in the 120-155°C range has been characterized by refractometry and infrared (IR) spectroscopy. The copolymer was a random ethylene-propylene resin and the IR techniques included tilted-film transmission as well as internal reflection, both using polarized radiation. The IR techniques yielded spectra corresponding to the machine, transverse, and through directions. Similarly, the refractometry gave refractive indices of both components of each laminate along all three axes. Results from the three techniques were compared and contrasted and the validity of the calculated internal reflectance spectra discussed. Practical methods to estimate the source and extent of errors in the latter technique from false radiation and contact problems were explored.
    Additional Material: 5 Ill.
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  • 4
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 22 (1984), S. 2051-2062 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The viscometric behavior of dilute solutions of the sodium salt of sulfonated polystyrene (0-6 mol % sulfonation level), with and without surfactant, is investigated to determine the extent of interaction as the structure of the solvent surfactant, and polymer concentration is varied. Reduced viscosity measurements confirm that formation of a polymer-surfactant complex in a relatively polar solvent is controlled to a large extent by charge-charge and hydrophobic forces. The magnitude of these specific interactions is dependent upon the relative polarity of the solvent medium. In a polar solvent, such as dimethylsulfoxide, the hydrophobic forces are strong enough to prevent expansion of the polymer chain at all surfactant concentrations studied. However, in a less polar medium (as in dimethylformamide) the hydrophobic forces are weaker and cannot prevent some chain expansion. It is interesting to note that in this solvent the polystyrene-cationic surfactant complex exhibits a polyelectrolyte effect. Finally, in a lower-polarity medium (cyclohexanone) where the hydrophobic forces are weak, solution behavior is dominated by the interaction of the surfactant with the intramolecular sulfonate ion-pair aggregates.
    Additional Material: 13 Ill.
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  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Zeitschrift für anorganische Chemie 512 (1984), S. 211-220 
    ISSN: 0044-2313
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Darstellung und physikochemische Untersuchung der Nickel (II)-Komplexe mit Salizylaldehyd-S-methylthiosemicarbazonSalizylaldehyd-S-methylthiosemicarbazon (H2L) bildet mit NiII in Gegenwart von NO3- und ClO4- paramagenetische bis-Ligand-Chelat-Komplexe und in Gegenwart von NCS-, CH3COO-, Py und γ-Picolin diamagnetische, quadratisch-planare mono-Ligand-Chelat-Komplexe. In den paramagnetischen Komplexen wird H2L als neutrale Molekel und auch als Monoanion (HL-) koordiniert, in diamagnetischen Komplexen ausschließlich als Monoanion, mit Ausnahme des Komplexes in Gegenwart von CH3COO-, wo sich Salizylaldehyd-S-methylthiose micarbazon als Dianion (L2-) koordiniert. Letztere Liganden entstehen infolge der Deprotonierung der NH2- neben der OH-Gruppe. Die Komplexe wurden durch Elementaranalyse, magnetische Messungen, IR, Elektronenspektren, molare Leitfähigkeit und TG-Analysen charakterisiert.
    Notes: Salicylaldehyde S-methylthiosemicarbazone (H2L) in the presence of ClO4- forms with NiII the paramagnetic octahedral bis(ligand) chelate complexes while in the presence of NCS-, CH3COO-, Py and γ-Pic it gives diamagnetic square planar mono(ligand) chelate complexes. In the paramagnetic complexes H2L is coordinated as a neutral molecule (H2L) and monoanion (HL-), and in diamagnetic ones only as a monoanion, except the complex obtained in the presence of CH3COO-, where it is coordinated as a dianion (L2-). The last form of the ligand is the result of deprotonation, besides OH-, the NH2-group. The complexes have been characterized by elemental analysis, magnetic measurements, i.r. and diffuse-reflection spectra, molar conductivity and TG analysis.
    Additional Material: 5 Ill.
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  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 645-656 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The acid-catalyzed polymerization of epichlorohydrin was modified by the addition of 1,4-butanediol diglycidyl ether to the reaction. The amount of diepoxide added and the method of addition were varied to produce a series of polymers with increased molecular weight, broad molecular weight distributions, and variations in hydroxyl functionality. Polyurethane networks were prepared from these polyols for the evaluation of elastomeric properties. The most obvious result was the lack of elastomeric network formation in the unmodified material when modified polyols produced elastomeric properties under the same conditions. Differences in properties between samples with more diepoxide added in the original polymerization generally showed trends to lower elongation and higher modulus. Changes in the method of addition of the diepoxide produced great differences in the toughness of the elastomers formed in the cure process.
    Additional Material: 4 Ill.
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  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 3129-3133 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new series of liquid-crystal polymers containing main-chain mesogenic units is reported. The general repeating unit is where n = 4, 5, 6, 7, 8, 10, or 12.
    Additional Material: 1 Tab.
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  • 8
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 117 (1984), S. 1977-1979 
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Säurekatalysierte Cyclisierung des En-Produkts aus α-Pinen und PTADAluminiumchlorid-katalysierte Reaktion des En-Produkts 2 aus 4-Phenyl-4H-1,2,4-triazol-3,5-dion (PTAD) und α-Pinen (1), des 1-(6,6-Dimelthyl-2-methylenbicyclo[3.1.1]hept-3-yl)-4-phenyl-1,2,4-triazolidin-3,5-dions, ergab 3,8,8-Trimelthyl-N-phenyl-4,5-diazatricyclo[4.2.1.03,7]nonan-4,5-dicarboxamid (6) in 78% Ausbeute. Auch Bortrifluorid-etherat, trockener Chlorwasserstoff und p-Toluolsulfonsäure katalysieren die Cyclisierung von 2 zu 6, aber nicht in diesem Maße. Der Mechanismus der Cyclisierung wird über eine Gerüstumlagerung der Carbenium-Ionen-Zwischenstufen gedeutet.
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  • 9
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metallcarbonyl-Synthesen, XVI1). Metall-Metall-Mehrfachbindungen: Synthese, Molekül- und Kristallstruktur von Tri-μ-carbonylbis([η5-pentamethylcyclopentadienyl)mangan](Mn ≡ Mn) - die erste Mangan-Mangan-DreifachbindungPhotolyse des Halbsandwich-Mangan-Komplexes (η5-C5Me5)Mn(CO)3 (1) in Tetrahydrofuran (THF) führt ohne Nebenreaktionen zum Solvenskomplex (η5-C5Me5)Mn(CO)2(THF) (2). Dieser ist im festen Zustand im deutlich unter 0°C liegenden Temperaturbereich haltbar, erleidet aber spontane CO-Eliminierung bei Raumtemperatur; dabei bildet sich der neue Zweikernkomplex (η5-C5Me5)2Mn2(μ-CO)3 (3). Während Elementaranalyse, Infrarot- und Massenspektren sowie die 1H- und 13C-NMR-Spektren dieser Verbindung eine hochsymmetrische dreifach Carbonylverbrückte Struktur zuweisen, stützt eine Einkristall-Röntgenstrukturanalyse das Vorliegen der ersten bisher bekannten Mangan-Mangan-Dreifachbindung (dMn - Mn 217.0(1) pm). Eine verbesserte Darstellung von Tricarbonyl(η5-pentamethylcyclopentadienyl)mangan (1) wird beschrieben.
    Notes: Photolysis of the manganese half-sandwich complex (η5-C5Me5)Mn(CO)3 (1) in tetrahydrofuran (thf) cleanly yields the solvent complex (η5-C5Me5)Mn(CO)2(thf) (2). Compound 2 is stable as solid at temperatures well below 0°C but undergoes spontaneous elimination of carbon monoxide at ambient temperature with concomitant formation of the novel dinuclear complex (η5-C5Me5)2-Mn2(μ-CO)3 (3). While elemental analysis, infrared and mass spectroscopy as well as the 1H NMR and 13C NMR spectra unequivocally demonstrate this compound to adopt a highly symmetrical triply carbonyl-bridged structure, a single-crystal X-ray diffraction study supports the presence of the first triple bond between manganese atoms (dMn - Mn 217.0(1) pm). An improved synthesis of tricarbonyl(η5-pentamethylclopentadienyl)manganese (1) is also described.
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  • 10
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 22 (1984), S. 17-28 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Plasma polymers synthesized by inductively coupled RF techniques have been investigated as a function of operating parameters for the isomeric perfluorinated diazines (pyrazine, pyrimidine, and pyridazine). A combination of ESCA and microanalytical studies shows that plasma polymers are produced by rearrangement mechanisms: the C/F and C/N stoichiometric ratios are similar to those of the starting monomers over a range of operating parameters. A comparison of rates of formation of plasma polymer films reveals distinctive differences between the isomeric diazines that suggest that equilibration of valence isomers occurs on a substantially slower time scale than for isomeric fluorinated benzenes5-9 which, in general, polymerize at essentially the same rates. In contrast to the remarkably low critical surface tension of plasma polymers based on perfluorobenzenes (ca. 20 dynes cm-2), the plasma polymer films from the perfluorinated diazines which are initially hydrophobic become hydrophilic in contact with water droplets. This is attributed to the hydrolytic instability of films associated with the labilizing influence of nitrogen on nucleophilic displacement of fluoride which is a feature of the chemistry of monomers.
    Additional Material: 9 Ill.
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