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  • 1
    Electronic Resource
    Electronic Resource
    Gas transport of hydrocarbon gases through smectic-A liquid-crystalline elastomers (1992)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 193 (1992), S. 2945-2960 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The transport behaviour of hydrocarbon gases through liquid-crystalline (l.c.) elastomers is investigated. For different l.c. elastomers exhibiting the smectic-A phase structure, diffusion and permeation coefficients and solubilities are measured as a function of temperature. The behaviour at the smectic-A to isotropic phase transformation is discussed and the permeabilities of propane through different l.c. membranes are compared with respect to their network type, spacer length and end group of the mesogens. In methacrylate networks with high phase transformation enthalpies a discontinuous behaviour is observed at the smectic to isotropic phase transformation temperature Tc, as expected for a first-order phase transformation. Depending on the chemical constitution of the membrane, the l.c. state can reduce or improve the gas transport compared to the isotropic state. With increasing flexibility of the membrane system  -  caused by a more flexible network, longer spacer or longer end group  -  the permeabilities exhibit significantly higher values. For all elastomers an increase of the ideal selectivities is observed in the smectic-A phase.
    Additional Material: 13 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1992.021931201
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    PVC modification with pyridine groups. Synthesis, characterization and transformation to ionomers (1998)
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 199 (1998), S. 2199-2204 
    Details
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The modification of PVC with 4-mercaptopyridine is described. The content of pyridine groups in the products is measured by NMR and IR spectroscopy. The degree of modification depends on the reaction conditions, and values of up to 70% are achieved without degradation or other appreciable side reactions. The tertiary amino groups in the polymer can be alkylated with iodides of varying chain length to form quantitatively quaternary pyridinium salt groups, leading to PVC ionomers and polyelectrolytes.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
  • 3
    Electronic Resource
    Electronic Resource
    Synthesis of adjustable poly(vinyl chloride) networks (1996)
    Weinheim : Wiley-Blackwell
    Macromolecular Rapid Communications 17 (1996), S. 15-23 
    Details
    ISSN: 1022-1336
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: 2-Mercaptobenzyl alcohol and 4-mercaptobenzyl alcohol were synthesized in good yields starting form thiosalicylic acid and p-toluenesulfonic acid, respectively. Poly(vinyl chloride) (PVC) reacts selectively with the thiol group of these bifunctional compounds leading to modified PVC with free hydroxy groups. In a second step the polymer chains can be partially crosslinked by reaction with hexamethylene diisocyanate. According to the degree of PVC modification, the network density of the resulting elastomers is freely adjustable.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/marc.1996.030170103
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    Paper (German National Licenses)
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  • 4
    Electronic Resource
    Electronic Resource
    Synthesis and characterization of novel poly(amide imide)s (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 61 (1996), S. 923-928 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Novel poly(amide imide)s having inherent viscosities in the range 0.89-1.56 dL/g were prepared by the method of low temperature polycondensation in solution of N,N-dimethylacetamide (DMA) from aromatic diamines and a new monomer: N-[4″-(chloroformylphenyl)-4′-iminobenzoyl]trimellitimide chloride. The polymers were soluble in polar aprotic solvents and essentially amorphous. They showed glass transition temperatures in the range 310-350°C and decomposition temperatures of 450-460°C. Polymer films, fabricated by casting polymer solutions in DMA, showed tensile strengths in the range 70-90 MPa and moduli values between 3000-4000 MPa. © 1996 John Wiley & Sons, Inc.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
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