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  • 1
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 991-1000 
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: To determine the behavior of a copolymer is dilute solution, a viscosity study has been performed on a polystyrene-polydimethylsiloxane block copolymer in three solvents presenting different thermodynamic conditions. The results are discussed in relation to a mixture of homopolymers and a segregated model. The unperturbed dimensions, obtained by the Stock-mayer-Fixman method, are intermediate between those of the parent homopolymers. The intrinsic viscosity measured in a good solvent, toluene, was close to the weighted averages of those of the corresponding homopolymers of equal molecular weight, but higher in decalin and in butanone, θ solvents for PS and PDMS, respectively. According to the low value obtained for the interaction parameter, the chain is slightly expanded as a result of the interactions between the unlike monomer units. Both segregation and random conformation would probably occur, depending on the quality of the solvent.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 1 (1963), S. 985-992 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Viscometric, light-scattering, and osmotic pressure measurements were carried out on poly(n-butyl methacrylate) fractions in methyl ethyl ketone and acetone. Relationships between the limiting viscosity number, the average molecular weight, and the mean dimensions were obtained. Heterogeneity corrections were applied to all relationships, assuming a Schulz-type distribution. Values of Φ, calculated according to the Flory-Fox equation, were found to be 2.3 × 1023 and 2.1 × 1023 in MEK and acetone, respectively. No significant trend with molecular weight was noticed in the range investigated, though the dependence of [η] on the mean radii of gyration is less than that predicted by the Flory theory.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 2 (1964), S. 4039-4045 
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Viscometric measurements were carried out on poly(n-butyl methacrylate) fractions in chloroform, benzene, toluene, and dioxane. Light-scattering and viscometric measurements on these fractions were carried out in isopropanol over a narrow range of temperatures. The Flory-Fox Θ-temperature was obtained by graphical interpolation on a plot of the second virial coefficient versus the reciprocal of the absolute temperature. Values of Φ, calculated according to the Flory-Fox equation were found to be abnormally low, notwithstanding the application of heterodispersity corrections, a mean value of 1.62 × 1023 being found in isopropanol in the temperature range investigated. The dependence of [η] on the mean radii of gyration is found to be less than that predicted by the Flory-Fox theory. The light-scattering dimensions systematically appear to be too large in the ideal solvent, a discrepancy that cannot be explained by accumulated experimental factors.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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