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  • 1
    Electronic Resource
    Electronic Resource
    Wirkung von Diisocyanat als reaktiver Koppler in TPU/PA6-Blends (1993)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 206 (1993), S. 21-38 
    Details
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: To improve materials performance like the temperature of deformation under flexural load of thermoplastic polyurethanes (TPU) blending with thermoplastics is sensible. A good compatibilization and phase adhesion of thermodynamical incompatible blend-components can be achieved by the use of the right coupling agents. In the case of blends with TPU and PA6 diisocyanate is given into the melt during the extrusion. Through the chemical reactions effects of compatibilization are achieved in the cases of blends with polyesterpolyurethanes and PA6 produced by extrusion and injection moulding and by reactions in solution, too. These could be perceived as consequence of MDI-initiated reactions within the phase boundary layer. The possible reactions with the PA6-phase will be discussed by the use of a model-system made in solution. No effects of compatibilization by MDI could be proved in the polyetherpolyurethan/PA6-system. The chemical characterization of the blends was realized by GPC and FTIR whereas the properties of the morphology are proved with the help of DSC, DMA and transmission electron microscopy (TEM).
    Notes: Zur Verbesserung der Werkstoffeigenschaften von thermoplastischen Polyurethanen (TPU), wie etwa der Wärmeformbeständigkeit, ist es sinnvoll, ein Blending mit Thermoplasten vorzunehmen. Eine gute Phasenverträglichkeit und Phasenhaftung bei thermodynamisch unverträglichen Blendkomponenten kann durch geeignete reaktive Koppler erreicht werden. Bei den Blends aus TPU and PA6 wird Diisocyanat während der Extrusion in der Schmelze eingebracht. Durch die ablaufenden chemischen Reaktionen werden bei extrudierten und verspritzten Blends und bei aus der Lösung erzeugten Systemen aus Polyesterpolyurethan und PA6 verträglichkeitsverbessernde Wirkungen erreicht. Diese wurden als Folge von mit 4,4′-Diphenylmethandiisocyanat (MDI) initiierten Reaktionen in der Grenzschicht erkannt, wobei die möglichen Reaktionen mit der PA6-Phase anhand eines Modellsystems aus der Lösung diskutiert werden. Bei Blends aus Polyetherpolyurethan und PA6 wurde keine Verträglichkeitsvermittlung durch MDI nachgewiesen. Die chemische Charakterisierung der Blends erfolgte durch GPC und FTIR, während die morphologischen Eigenschaften mittels DSC, DMA und Elektronenmikroskopie dokumentiert wurden.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1993.052060103
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Die Abhängigkeit des Kontraktionsfaktors von der Molmasse bei Polyethylenen niederer Dichte (1980)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 31 (1980), S. 382-387 
    Details
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: By means of elution fractionation and characterising the fractions by viscometry and GPC the lg gη vs. lg M dependences of 13 LD-PE samples are determined. The lg gη vs. lg M curves of the LD-PE obtained with a tubular reactor, contrarily to the LD-PE obtained with an autoclave, are stagelike in the range of molecular mass lower than 105 g/mol and have a different slope beyond 105 g/mol. Suggestions to explain the results are presented and the influence of this differences on measuring of molecular mass distribution by GPC is estimated.
    Notes: Die lg gη-lg M-Abhängigkeiten von 13 PE-ND-Proben wurden durch Elutionsfraktionierung und Charakterisierung der Fraktionen mittels Viskosimetrie und GPC bestimmt. Ethylenpolymerisate nach dem Rohrreaktorverfahren zeigen im Gegensatz zu Polymeren nach dem Autoklavenverfahren einen stufenförmigen Verlauf der lg gη-lg M-Abhängigkeit im Molmassenbereich unter 105 g/mol sowie einen unterschiedlichen Abfall des gη-Wertes über 105 g/mol. Es werden Vorschläge zur Erklärung der Befunde gemacht und die Auswirkungen dieser Unterschiede auf die Bestimmung der MMV durch GPC abgeschätzt.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1980.010310609
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Characterization of low molecular weight carboxyl-terminated polyamides obtained by reactive extrusion of polyamide 6 with trimellitic anhydride (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 62 (1996), S. 2053-2060 
    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: Reactive extrusion has been applied as a very effective and fast process for controlled chemical degradation of a commercial polyamide 6 with trimellitic anhydride in the melt. A reaction mechanism based mainly on the amide/anhydride reaction has been discussed and confirmed by measurements of the solution viscosity, end group analysis, SEC, NMR, and IR spectroscopy. The systematic loss of molecular weight of the polyamides resulting from PA chain repture and the formation of imide linkages and carboxyl end groups were investigated. The theoretical values of molecular weight and end group concentration of the obtained oligoamides predicted by the reaction mechanism are in good agreement with the experimental ones. © 1996 John Wiley & Sons, Inc.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
  • 4
    Electronic Resource
    Electronic Resource
    LC multiblock copolymers containing polysulfone segments. I. Synthesis and morphology (1996)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 62 (1996), S. 1819-1833 
    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: Multiblock copolymers offer the possibility to combine the properties of different polymers. Thus, new materials with tailor-made unique properties are available by coupling of different suitable polymeric segments. The goal of the work discussed in this paper was to combine advantageous properties of liquid-crystalline polymers (LCP) with those of polysulfone (PSU). Therefore, liquid crystalline poly(ethylene terephthalate-co-1,4-oxybenzoates) were connected with PSU oligomers. Chemically homogeneous multiblock copolymers with high molecular weight were obtained by a melt transesterification procedure. It was demonstrated by wide angle x-ray scattering (WAXS), polarizing microscopy, transmission electron microscopy (TEM), and differential scanning calorimetry (DSC) that the properties of the multiblock copolymers (solid phase structure, phase behavior, morphology, glass transition, and melting behavior) can be balanced by the segment length of the incorporated blocks. The investigations clearly reveal the existence of a two-phase structure. However, a change of properties compared to the corresponding homopolymers refers to certain interactions between the phase due to the chemical connection of the LCP and PSU segments. © 1996 John Wiley & Sons, Inc.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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    Paper (German National Licenses)
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