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  • 1
    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: A water soluble ionomer with natrium propanesulfonate groups was prepared based on a linear polyurethane with high content of —NHCOO— structures. This compound was used both as macromolecular electrolyte and dopant ion in electrochemical polymerization of pyrrole, obtaining a molecular level polypyrrole-propanesulfonate polyurethane composite with electroconductive properties. © 1993 John Wiley & Sons, Inc.
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
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  • 2
    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: Durch Menschutkin-Reaktion wurden Polyurethane mit kationischen Viologen-gruppen hergestellt. Die photochromen Eigenschaften dieser Polymeren in einer Poly(vinylalkohol)-Matrix wurden mit UV- und Laserlicht untersucht.
    Notes: The Photochromic properties by UV and laser irradiation of cationic polyurethanes with viologen groups introducted by Menschutkin reaction were studied and poly(vinylalcohol) was used as matrix.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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  • 3
    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: Das Viskositätsverhalten verdünnter Lösungen von Sulfobetain-Polyurethanen in Dimethylformamid sowie der Einfluß von Salzen einiger ein- und zweiwertiger Metalle auf die Viskosität wurden untersucht. Dabei zeigte sich, daß sich diese Polyurethan-Zwitterionomeren wie Polyelektrolyte verhalten.In aus diesen Polymeren hergestellten und mit zweiwertigen Metallen komplexierten Filmen bilden sich im Schwefelwasserstoffstrom Metallsulfide. Die höhere Leitfähigkeit der mit H2S behandelten Filme deutet auf eine Struktur mit Mikrophasenseparation hin.
    Notes: The viscosimetric behaviour of diluted DMF solutions of some sulfobetaine polyurethanes and also the influence of some mono- and bivalent metal salts were studied. The study showed that polyurethane zwitterionomers behave as polyelectrolytes.Films of these polymers complexed with bivalent metals can form, in situ, particles of metal sulfides by exposure to slow H2S flow. Preliminary results show an increased conductivity of films treated with H2S, suggesting a microphase segregation structure.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 4
    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: Die mechanischen und dielektrischen Relaxationseigenschaften von Sulfobetain-Polyurethanionomeren auf Polyesterbasis wurden mit Zug-Dehnungs-Versuchen und thermisch stimulierten Depolarisationsstrom-Methoden (TSDC) untersucht und mit den Eigenschaften von nichtionischen Polyurethanen sowie Derivaten mit Pb2+ bzw. Co2+ verglichen. Die Einführung ionischer Zentren in die Polyurethankette verbessert die Zugfestigkeiten und verändert die TSDC-Spektren. Diese Effekte werden auf eine Verbesserung der Mikrophasensegregation zurückgeführt. Eine Komplexierung mit Pb2+ bzw. Co2+ vermindert die Zugfestigkeiten, was darauf hindeutet, daß durch eine teilweise Neutralisierung ionischer Zentren eine homogenere Phasenmischung erreicht wird. Die Behandlung mit H2S führt durch Clusterbildung der Metallsulfide PbS bzw. CoS zur Entstehung halbleitender Mikrophasen, wodurch die Zugfestigkeiten leicht erhöht und die TSDC-Spektren verändert werden.
    Notes: Tensile and dielectric relaxation properties of sulfobetaine polyurethane ionomers based on polyesters were studied comparatively to the non-ionic polyurethane and derived compounds with Pb2+ and Co2+, using stress-strain and thermally stimulated depolarization currents (TSDC) methods. Introduction of ionic centers into polyurethane chain improves the tensile properties and modifies the TSDC spectra. These effects are assigned to an enhancement of the microphase segregation. Complexation with Pb2+ and Co2+ diminishes the tensile properties, suggesting that an increase of phase mixing occurs determined by a partial neutralization of ionic centers. Treatment with H2S slightly increases tensile properties and changes TSDC spectra owing to the presence of the semiconducting microphases formed by clustering of the metal sulfides PbS and CoS, respectively.
    Additional Material: 4 Ill.
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  • 5
    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: Polyurethane and Polyetherurethane vom Elastomer-Typ mit nitroaromatischen Gruppen wurden hergestellt und mit UV-Licht in Lösung bestrahlt. Der Einfluß der UV-Strahlung auf die UV-Absorptionseigenschaften wurde untersucht und mit dem einer Modellsubstanz verglichen. Die UV-Bestrahlung bewirkt eine Intensitätsabnahme der charakteristischen UV-Absorptionsbanden und eine Verringerung des Molekulargewichts.
    Notes: Elastomer-type polyether urethanes and polyether urethane cationomers with nitroaromatic groups were prepared and the effect of UV irradiation on their characteristics was evaluated comparatively with a model compound. The photobehavior by UV irradiation with a high-pressure Hg lamp was studied in solution, following the change of absorption bands characteristic for nitro structures as a function of irradiation time. UV irradiation causes diminution of the intensity of characteristic UV absorption bands and a decrease of molecular weight.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 231 (1995), S. 25-33 
    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: Die Viskosität verdünnter Lösungen in Wasser oder DMF von Polyurethan-Ionomeren mit Natriumsulfopropylgruppen an den Urethan-Stickstoffatomen wurde untersucht. Bei Temperaturen zwischen 25 und 60°C zeigte sich ein Polyelektrolyteffekt, der auch nach Zugabe von Natriumchlorid erhalten blieb. Dies läßt sich durch Coulombsche Wechselwirkungen zwischen den Ladungsträgern und eine Tendenz zur Aggregation in separierten Domänen (begünstigt durch die spezifische molekulare Architektur der Polymeren) erklären.
    Notes: Aqueous and DMF-diluted solutions of polyurethane ionomers with sodium propanesulfonated groups at urethanic nitrogen atoms were studied by viscometry. A polyelectrolyte effect was evidenced at temperatures between 25 and 60°C, and it was preserved when NaCl was added to solutions.The coulombic interactions between charged groups and a tendency to aggregation in separated domains (favoured by specific molecular architecture of polymers) explain the observed solution properties.
    Additional Material: 7 Ill.
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  • 7
    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: Aus Poly(oxytetramethylen), 4,4′-Bibenzyldiisocyanat, N-Methyldiethanolamin als Kettenverlängerer und Acrylsäure/Polyacrylsäure als Quaternisierungsagens wurden Poly(etherurethan)-Kationomere hergestellt. In aus diesen Kationomeren hergestellten Filmen wurde Pyrrol (15 Gew.-%) in Gegenwart von CuCl2 polymerisiert. Die Filme wurden mittels dynamisch-mechanischer Analyse, Thermogravimetrie und Differentialthermoanalyse charakterisiert. Die elektrische Leitfähigkeit beträgt für den Film ohne Polypyrrol 7.5 · 10-12 Ω-1 cm-1 und mit Polypyrrol 4.5 · 10-6 Ω-1 cm-1.
    Notes: Poly(ether urethane) cationomers based on poly(oxytetramethylene), 4,4′-bibenzyldiisocyanate, N-methyldiethanolamine as chain extender, and acrylic acid/poly(acrylic acid) as quaternization agent were synthesized. Pyrrole (15 wt.%%) was polymerized in films of the ionomer containing CuCl2. The films were characterized by dynamic mechanical analysis, thermogravimetry and differential scanning calorimetry. The electric conductivity of the film without polypyrrole is 7.5 · 10-12 Ω-1 cm-1, while incorporation of polypyrrole increases the conductivity to 4.5 · 10-6 Ω-1 cm-1.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of poly(vinyl chloride) (PVC), head-to-head macroradical plays an essential role in the formation of branches and the appearance of interruption processes that lead to labile unsaturated end groups. A reaction mechanism is suggested to explain these processes and the method of formation of internal double bonds as a result of transfer to polymer. The transfer to monomer can occur only by atom acceptance by the macroradical and not by the monomer giving up an atom.
    Additional Material: 1 Tab.
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  • 9
    ISSN: 1572-8943
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung In der Literatur vorgeschlagene kinetische Gleichungen für thermische Zersetzungsreaktionen können bei niedrigen Konversionen mit der Gleichung αb=Dp(x) genähert werden. Diese Gleichung offenbart unter isothermen Bedingungen drei Verhaltensweisen, wie an der thermischen Dehydrochlorierung von Polyvinylchlorid bewiesen wird. Die kinetischen Parameter wurden mittels eines Computerprogrammes ermittelt und ihre Leistungsfähigkeit überprüft. Das Rechenverfahren wurden an einigen Polyvinylchloridmakromodellen getestet.
    Abstract: Резюме Кинетические уравне ния, предложенные в литературе для реакц ий термического разложения, могут быт ь при низкой степени п ревращения описаны уравнениемα b =Dp(x). Это уравнение показывае т три различных харак тера термического поведе ния в изотермических условиях, как это было доказано на примере термического дегидр охлорирования полив ияилхлорида. Кинетические параме тры были определены с помощью математической прог раммы, действие которой был о испытано. Метод расч ета был применен для некотор ых макромоделей поливинилхлорида.
    Notes: Abstract Kinetic equations proposed in the literature for thermal decomposition reactions may be approximated at low conversions by the relation: αb=Dp(x). This equation reveals three kinds of behaviour under isothermal conditions, as evidenced in the thermal dehydrochlorination of Polyvinylchloride. The kinetic parameters were determined with a computing program and its performances were tested. The calculation method was applied to some Polyvinylchloride macromodels.
    Type of Medium: Electronic Resource
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  • 10
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary A chemical method to determine the tertiary chlorine content in PVC based on the reaction of brominated PVC samples with phenol was established. A good agreement between the long branches content and the tertiary chlorine content was found. The thermal stability of the brominated PVC increased.
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