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  • 1985-1989  (4)
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Polymer bulletin 21 (1989), S. 555-562 
    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 In view of a study on the preparation and properties of polyurethanes containing furan rings, it was deemed necessary to carry out a preliminary investigation on the synthesis and characterization of simple furanic urethanes given the paucity of information available on this family of compounds. Three types of combinations were tested, viz; (i) furanic alcohols plus non-furanic isocyanates; (ii) non-furanic alcohols plus furanic isocyanates; (iii) furanic alcohols plus furanic isocyanates. The 21 urethanes thus obtained were fully characterized: they are stable (with one exception) and their synthesis is not marred by secondary reactions, ie the furan ring does not introduce “side effects”.
    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: Die Resultate von Untersuchungen über die chemische Wechselwirkung zwischen einigen monofunktionellen Modellverbindungen, die die Struktur und Reaktivität von wärmehärtbaren Phenol- und Harnstoff-Formaldehyd-Harzen simulieren, mit Holzkomponenten (Hemicellulosen, Cellulose und Lignin) werden dargelegt. Während Hemicellulosen deutlich dazu neigen, Kondensationsprodukte mit diesen Modellverbindungen zu ergeben, reagieren Lignine in manchen Fällen weniger leicht und abhängig davon, durch welchen Prozeß sie gewonnen worden sind, und abhängig von der Art der Modellverbindung. Cellulose reagierte wegen ihrer Kristallinität nicht unter den gegebenen Bedingungen.
    Notes: Results are presented on the chemical interactions occurring when some monofunctional model compounds simulating the structure and reactivity of thermosetting phenol- and urea-formaldehyde resins are mixed with wood components (hemicelluloses, cellulose, and lignins). Whereas hemicelluloses clearly show a propensity to give condensation products with these model compounds, lignins can react less readily in some instances depending on the delignification procedure used to isolate them and on the type of model compound. Cellulose did not react under the conditions chosen, mostly because of its crystalline character.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Basel : Wiley-Blackwell
    Die Makromolekulare Chemie, Rapid Communications 9 (1988), S. 255-256 
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Acta Polymerica 40 (1989), S. 613-618 
    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: Kinetische Untersuchungen der durch Trifluoressigsäure katalysierten Polymerisation von 2-Ethenyl-furan in Methylendichlorid zeigten ein Verhalten von pseudo-zweiter Ordnung mit Abweichungen in Richtung erster oder dritter Ordnung in Abhängigkeit vom Konzentrationsbereich des Initiators. Die Geschwindigkeitskonstante ist direkt proportional der Ausgangskonzentration des Initiators und umgekehrt proportional zur Ausgangskonzentration des Monomers. Während der Polymerisation nimmt die Säurekonzentration infolge der Bildung stabiler polymerer Ionen ab. Weiterhin wird vom Beginn der Polymerisation an eine alkylierung des Furanrings beobachtet. Zur Erklärung der experimentellen Ergebnisse wird ein pseudo-Copolymerisationsmechanismus vorgeschlagen.
    Notes: The kinetic studies of 2-ethenyl furan polymerization in methylene dichloride catalyzed by trifluoroacetic acid, showed a pseudo second order behaviour with deviations to the first or third order in dependence on the concentration range of the initiator. The rate constant is directly proportional to the square of the initial concentration of initiator and inversely proportional to the initial concentration of monomer. During the polymerization the acid concentration decreases as a consequence of the formation of stable polymeric ions. Moreover, the alkylation of furan ring from the beginning of the polymerization is observed. A pseudo-copolymerization mechanism is proposed to justify the experimental results.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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