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  • 1
    Electronic Resource
    Electronic Resource
    Adsorptionsmodifizierung der oberfläche von mineralischen polymerfüllstoffen als die methode deren aktivierung (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 2885-2892 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The process of modifying the surface of particles of dispersed polymer fillers, using tensides, has been studied. The main principles were established with regard to the effect of modification of titanium dioxide and kaolin on the structure formation in solutions and block formations of chlorinated poly(vinyl chloride) resin and rubber, depending on the nature and concentration of the modifier. The decisive part played by chemisorption of the tenside in lyophilization (water-repellency treatment) of the surface of the filler and its activation, as a structure former, has been elucidated.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170161114
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  • 2
    Electronic Resource
    Electronic Resource
    Collapsed conformation of poly(methacrylic acid) chain containing nonionic hydrophilic units (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 2183-2190 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Copolymers of methacrylic acid (MAA) and a nonionic hydrophilic monomer N-vinylpyrrolidone (NVP) were synthesized by polymerization in aqueous solution in the absence of metal ions. The NVP content of the copolymers ranged from 2 to 36 mole % with sequences of MAA interrupted at random by a single unit of NVP at all compositions. The pH-induced conformational transition of these copolymers was followed by potentiometric titration and viscosity studies and the results were compared with those of pure poly(methacrylic acid) (PMAA). The negative free energy of transition from the un-ionized compact from to expanded structure showed a gradual decrease with increasing NVP content, and the collapsed conformation observable for PMAA at low degrees of ionization (0 〈 α 〈 0.3) disappeared at NVP contents greater than 15 mole%. These findings are supported by viscosity data. The results suggest that long-range methyl-methyl hydrophobic contacts still possible in higher NVP content copolymers are not sufficient to bring about the collapse of the molecule and a minimum average sequence length of about 20 MAA units is required to compact the molecule. Hydrophilic “shielding” of MAA chains by NVP segments could also partly destabilize the collapsed structure.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160908
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  • 3
    Electronic Resource
    Electronic Resource
    Study of kinetic regularities and mechanism of methyl methacrylate radical polymerization in the presence of orthophosphoric acid (1978)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 16 (1978), S. 2199-2215 
    Details
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Photoinitiated homophase polymerization of methyl methacrylate (MMA) at 25°C in the presence of a complexing agent, orthophosphoric acid (H3PO4), was studied. It was found that in addition to the increase in initial polymerization rates and molecular weights of PMMA the system MMA/H3PO4 reveals postpolymerization that does not retard with time and is accompanied by an increase on average molecular weight. Macroradicals, lifetimes of which grow considerably in the presence of the complexing agent, are shown to be responsible for the termination-free postpolymerization in this system by the living chain mechanism. The effect of various factors on the kinetics of postillumination polymerization was studied. A drastic decrease in the rate of bimolecular termination of poly(methyl methacrylate) radicals was shown to be related to the change in conformational properties and to the association of propagation chains via complexing with H3PO4. The mechanism of polymerization in this system was discussed.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1978.170160910
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  • 4
    Electronic Resource
    Electronic Resource
    Excluded volume study of a sulfonate-containing polyelectrolyte in salt solutions (1975)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 13 (1975), S. 1705-1719 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Chain characteristics of a linear sulfonate-containing homopolymer, sodium poly(3-methacryloyloxypropane-1-sulfonate), in aqueous salt solutions (ionic strength, Cs = 0.01N to 5N NaCl) have been investigated by light scattering and intrinsic viscosity. The molecular weight (M̄w)-viscosity relation can be well described by the Mark-Houwink and the Stockmayer-Fixman equations. The coil is highly expanded even in the most concentrated NaCl solution (6N), and no 1:1 electrolyte was found to precipitate this polymer.A linear relation was observed between the viscosity expansion factor, α3η, and (M̄w/Cs)1/2. Examination of the data in terms of theories for excluded volume and hydrodynamic interaction suggests that the coil experiences dominant hydrodynamic interaction, corresponding to a nondraining coil, and the second virial coefficient and coil expansion at high Cs can be correlated by the Flory-Krigbaum-Orofino equation. Results for this polymer are compared with those for other polyelectrolytes, and are discussed in terms of chain structure, flexibility, and hydrophobicity.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1975.180130905
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  • 5
    Electronic Resource
    Electronic Resource
    Studies of molecular relaxation of poly(propylene oxide) solutions by dielectric relaxation and brillouin scattering (1976)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 14 (1976), S. 1877-1890 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Dielectric relaxation and Brillouin scattering are jointly used in studying molecular relaxation in poly(propylene oxide) (PPO) and its solutions in methylcyclohexane. The dielectric method was applied to the more concentrated (100%, 80%, 60%, by volume) solutions over a wide temperature and frequency range (30 Hz to 8 GHz) in order that the variation in activation energy characteristic of a glass-forming substance could be delineated. The present work extends previous work on the undiluted polymer to higher frequencies so that range of 12 decades in the dielectric loss maximum fmax as a function of temperature is now available. The “Antoine” equation is found to represent the behavior of log fmax, of the bulk concentrated solutions very well. The more dilute (40%, 20%) solutions were studied only in the high-frequency (GHz) region since phase separation occurred at low temperatures. Both the temperature and dilution effects were interpreted in terms of free-volume theory. Brillouin scattering spectra were obtained at several scattering angles and a wide range of temperatures. A maximum in the curve of hypersonic attenuation versus temperature was observed in each polymer solution. The attenuation maximum shifts toward lower temperature upon dilution, in agreement with the dielectric relaxation result. The Brillouin scattering follows different activation parameters and evidences a more rapid process than does the dielectric relaxation. It is speculated that it monitors a secondary or subglass relaxation, due perhaps, to damped torsional oscillations.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1976.180141012
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  • 6
    Electronic Resource
    Electronic Resource
    The elongation and time dependence of the crystallinity of low-density polyethylene (1975)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 13 (1975), S. 1945-1957 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It has been presumed in studies of the orientation of low-density polyethylene and its time dependence that the degree of crystallinity remained constant with elongation and did not vary with time following elongation. This paper represents a test of this hypothesis by several methods. The change in crystallinity accompanying stretching has been followed by a modification of an x-ray method for uniaxial orientation proposed by Ruland in which diffraction peaks are resolved into crystalline and amorphous components and their respective areas are determined by two-dimensional integration over both the Bragg angle and the azimuthal angle of diffraction. The weight-fraction crystallinity is then determined from the ratio of the weighted crystalline area to the total area. There appears to be no significant variation in crystallinity up to 50% sample elongation for both slowly and rapidly stretched samples at room temperature. The dynamic crystallinity change accompanying small amplitude vibration has also been determined by the dynamic x-ray diffraction technique and found to be negligible over a wide range of frequency. The degree of crystallinity has also been evaluated from the absolute infrared absorbance of crystallinity-sensitive bands and has also been found to be independent of elongation at room temperature up to 80% elongation. Changes have also been observed by this method during relaxation at constant length following rapid extension and have also been found to be negligible. These results also indicate negligible changes in rotational isomer population. Consequently, we conclude that changes observed during relaxation and vibration arise from orientational changes rather than changes in the degree of crystallinity.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1975.180131009
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  • 7
    Electronic Resource
    Electronic Resource
    A Raman study of the phase transition in crystalline trans-1,4-polybutadiene (1976)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 14 (1976), S. 521-529 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Raman spectroscopy has been used to analyze the characteristics of the crystal-crystal phase transition of trans-1,4-polybutadiene. The low- and high-temperature structures were found to coexist at the transition. The Raman spectra obtained at high temperature can be understood on the basis of the change in chain conformation associated with the phase transition.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1976.180140312
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  • 8
    Electronic Resource
    Electronic Resource
    Influence of pressure and chemical structure on the thermal conductivity of vitreous poly(alkyl methacrylates). I (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 15 (1977), S. 1199-1210 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The influence of pressure on the thermal conductivity K of four vitreous poly(alkly methacrylate) polymers has been measured by steady state techniques. The measurements were made under pressures up to 2 kbar and over a temperature range between 173 and 300°K. For each member of the homologous series, K was found to increase with applied pressure. Shifts in thermal conductivity transition temperatures (attributed to glass transition phenomena) of 25, 26, and 16°C per kbar of applied pressure were observed for poly(methyl methacrylate), poly(ethyl methacrylate), and poly(n-isobutyl methacrylate).
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.180150706
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  • 9
    Electronic Resource
    Electronic Resource
    Chemical origin of thermally stimulated discharge currents in polyacrylonitrile (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 15 (1977), S. 485-499 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Thermally stimulated discharge has been used in the past to diagnose and estimate the magnitude of electrical polarization in polymers. Nevertheless, molecular characterization of operative phenomena by this technique alone is often a difficult task. In the present work, infrared attenuated total reflection spectroscopy has been used to investigate the origin of thermally stimulated discharge currents near 200°C in externally unpolarized films of polyacrylonitrile (PAN). Spectroscopic analysis of thermally degraded films reveals some unsaturation of the PAN backbone and possibly the generation of cyanide ions. Opposite surfaces in a solvent-cast film give different spectra, indicating a gradient in chemical degradation products across the film thickness. Data suggest that nonuniform generation of charged species and unsaturated bonds gives rise to internal potentials in PAN. The origin of thermally stimulated currents in PAN near 200°C is thus believed to be associated with the onset of chemical degradation.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.180150308
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  • 10
    Electronic Resource
    Electronic Resource
    Light scattering studies of mixtures and fractions of linear polyethylene (1977)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 15 (1977), S. 1189-1198 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Previous work on the small-angle light scattering of polyethylene films, to determine the supermolecular structure, has been continued. One of the main efforts has been the study of a binary mixture whose low molecular weight component forms well defined spherulites and whose high molecular weight component yields a poorly defined rod-like morphology. The addition of the high molecular weight fraction causes a progressive deterioration of the initial spherulitic morphology; a relatively small amount of the high molecular weight species causes a major decrease in the spherulitic size. However, there are no indications of any spherulitic structures when the weight fraction of the high molecular weight species is 0.5 or greater. The isothermal crystallization of a fraction M = 6.6 × 105 was also studied. Spherulites were formed at low crystallization temperatures while at the higher crystallization temperatures the morphology became nondistinct. Preliminary studies with solvents indicate that high molecular fractions, which do not form spherulites when crystallized in the pure state, do so when crystallized from highly swollen solutions.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1977.180150705
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