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  • 1
    Electronic Resource
    Electronic Resource
    Higher aliphatic aldehyde polymers, VII: poly(n-decaldehyde) (1978)
    Springer
    Monatshefte für Chemie 109 (1978), S. 1241-1261 
    Details
    ISSN: 1434-4475
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Die Polymerization vonn-Decaldehyd zu einem krystallinen Polymeren von mittlerem Molekulargewicht wurde mit Lithium-tert-butylat in Methylcyclohexan unter genauer Temperaturkontrolle durchgeführt. Poly(n-decaldehyd) (PDA) wurde mittels spektroskopischen Methoden (IR und PMR) charakterisiert, und durch Abbau in der Gegenwart von 2,4-Dinitrophenylhydrazin wurde die Polyacetalstructur des Polymeren bestätigt.PDA hat einen “Doppelschmelzpunkt” ähnlich anderer aliphatischer Polyaldehyde mit mehr als vier Kohlenstoffatome in der Seitenkette.DSC-Untersuchungen zeigten in der ersten Übergangsregion, der der Seitenkettenkristallisation, daß drei endotherme Spitzen zwischen 45 und 65° beobachtet werden konnten. DasDebye-Scherrer-Diagramm des krystallinenPDA war ähnlich dem anderer Polyaldehyde, aber mit größerer Einheitszelle.PDA wurde bei einer Temperatur von 53°C in einem Rheometer extrudiert und gab Fasern, deren Röntgenstreuung mittlere Orientierung zeigte.
    Notes: Abstract n-Decaldehyde (DA) was polymerized to crystalline poly(n-decaldehyde) (PDA) of reasonable molecular weight in methylcyclohexane (MCH) solvent with lithiumtert-butoxide (LTB) as the initiator under carefully controlled temperature conditions. The polyacetal structure ofPDA was established by IR and PMR spectroscopy as well as by the characteristic degradation of the polymer in the presence of 2,4-dinitrophenylhydrazine.PDA had the dual melting behavior typical of aliphatic polyaldehydes with four or more side chain carbon atoms. The DSC scans of crystallinePDA in the first, or side chain, transition region showed as many as three endothermic peaks between 45 and 65°C. The X-ray diffraction pattern of crystalline PDA was similar to that which had been observed for other polyaldehydes but with a larger unit cell.PDA was extruded at 53°C in a capillary rheometer and gave a filament whose X-ray diffraction pattern indicated medium orientation effects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00913025
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  • 2
    Electronic Resource
    Electronic Resource
    Haloaldehyde polymeres XIII. Polydibromofluoroacetaldehyde (1979)
    Springer
    Monatshefte für Chemie 110 (1979), S. 453-471 
    Details
    ISSN: 1434-4475
    Keywords: Haloaldehyde polymers ; Dibromofluoroacetaldehyde, Polymerization ; Ceiling temperature, Thermal degradation ; Copolymerization
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zusammenfassung Dibromfluoracetaldehyd (DBFA) wurde aus Dibromfluoressigsäuremethylester durch Addition des Lithiumaluminiumhydrids zum Ester hergestellt. Das zuerst erhalteneDBFA-Hydrat wurde zum freien Aldehyd dehydratisiert. Der Dibromfluoressigsäuremethylester wurde unter gleichzeitiger Herstellung von Bromdifluoressigsäuremethylester durch Luftoxydation von 1,1-Dibrom-2,2-difluorethen erhalten. Das Oxydationsprodukt, das die Säurehalogenide enthielt, wurde mit Methanol behandelt und gab eine Estermischung, die durch Destillation getrennt werden konnte.DBFA wurde mit anionischen und kationischen Initiatoren zu unlöslichen, kristallinen Poly-DFBA polymerisiert. Der polymereDBFA wurde quantitativ bei erhöhter Temperatur zu monomeremDBFA abgebaut. Copolymerisation vonDBFA mit Chloral gab ein Copolymer mit der gleichen Copolymerzusammensetzung wie das ursprüngliche Verhältnis der zwei Monomeren.DBFA copolymerisierte auch mit Phenylisocyanat zu Copolymeren mit Acetal- und Urethangruppen in der Kette.
    Notes: Abstract Dibromofluoracetaldehyde (DBFA) was prepared by reducing methyl dibromofluoroacetate with lithium aluminium hydride (LAH) at low temperatures whereby theLAH was added to dibromofluoroacetate. The initially obtainedDBFA hydrate was dehydrated to the free aldehyde. Methyl dibromofluoroacetate was synthesized together with methyl bromodifluoroacetate by air oxidation of 1,1-dibromo-2,2-difluoroethylene. The mixture of oxidation products, consisting of two acid halides, was treated with methanol and gave a mixture of the methyl esters which here separated by distillation. DBFA was polymerized with anionic and cationic initiators to crystalline insoluble poly-DBFA. Poly-DBFA degraded quantitatively at elevated temperatures to monomericDBFA. Copolymerization ofDBFA with chloral gave copolymers with nearly the same comonomer composition as the feed.DBFA was also copolymerized with phenyl isocyanate to a copolymer which contained acetal and urethane linkages.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00911933
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  • 3
    Electronic Resource
    Electronic Resource
    Head-to-head polymers, 14Part 13: cf.18. Part 15: F. Laupretre, L. Monnerie, O. Vogl, Eur. Polym. J., in press.. Thermal degradation of head-to-head and head-to-tail polystyrenes and poly(vinylcyclohexane)s (1979)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 180 (1979), S. 2295-2302 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The thermal degradation behavior of head-to-head (H-H) and head-to-tail (H-T) polystyrenes and poly(vinylcyclohexane)s has been investigated by direct pyrolysis in a mass spectrometer. Both H-H and H-T isomers show only small differences in their initial temperatures of decomposition but remarkably different degradation processes. Whereas H-T polystyrene decomposes in accordance with earlier investigations mainly by a radicalic depolymerization into the monomer and yields only a small amount of dimer and trimer, the H-H polystyrene shows no unzipping and only a statistic degradation into oligomeric styrenes. The formation of stilbene is a diagnostic reaction of H-H polystyrene. The pyrolysis-mass spectra of H-H and H-T poly(vinylcyclohexane)s are more similar than those of the polystyrenes but the favored thermal cleavage between the two tertiary carbon atoms or next to the tertiary carbon atoms of the polymer backbone chain leads to some characteristic fragments, e.g. 1,3-dicyclohexylpropene from the H-T and 1,2-dicyclohexylethane from the H-H polymer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1979.021801003
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