ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Polymer and Materials Science  (6)
  • Early hominid  (2)
Collection
Keywords
Publisher
Years
  • 1
    Electronic Resource
    Electronic Resource
    NMR investigations on copolymers of maleic anhydride with ethylenePart of a lecture at the IUPAC Symposium on Macromolecular Chemistry in October 1978 in Tashkent/USSR (1980)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 31 (1980), S. 582-586 
    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: Mit hochauflösender 1H- und 13C-Kernresonanz wurden Maleinsäureanhydrid-Ethylen-Copolymere untersucht, die sich im Herstellungsprozeß stark unterscheiden. Die Untersuchungen zeigten, daß sowohl Fällungs- als auch Hochdruckpolymerisation zu alternierendem Einbau der MSA-Einheiten in die Copolymerkette führen. Die in der Mikrostruktur festgestellten Unterschiede resultieren aus nachträglichen Modifizierungsreaktionen, die teils im Fällungsprozeß durch Alkohol und teils durch Luftfeuchtigkeit unter Aufspaltung des Anhydridringes spontan eintreten könne. Sowohl mit 1H- als auch mit 13C-Resonanz sind diese Modifizierungsreaktionen gut beobachtbar. Des weiteren weisen die 13C-NMR-Spektren darauf hin, daß die Copolymere aus verschiedenen Stereokonformeren aufgebaut sind.
    Notes: The microstructure of copolymers of maleic anhydride with ethylene which were synthesized in two processes differing significantly from one another was studied by means of 1H- and 13C-NMR. The precipitation polymerizates as well as the products synthesized under high pressure have the same basic structure. The maleic anhydride units are found to alternate with ethylene units in the macromolecules. The observed differennces in the microstructure are results of supplementary modification reactions which may take place spontaneously in the precipitation process by alcohols or during storage by atomospheric humidity with the splitting-up of the anhydride ring. 1H- and 13C-NMR spectroscopy proved as efficient methods for studying these modification processes. The 13C-NMR spectra allow the conclusion that the microstructure of maleic anhydride copolymers consist of different stereo conformations which occur with different probability.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1980.010310910
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Reconstruction of the maxillary dental arcade of Garusi Hominid 1
    Amsterdam : Elsevier
    Journal of Human Evolution 15 (1986), S. 325-332 
    Details
    ISSN: 0047-2484
    Keywords: Australopithecus ; Early hominid ; Garusi ; Hadar ; premaxilla
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/S0047-2484(86)80015-X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Reconstruction of the maxillary dental arcade of Garusi Hominid 1
    Amsterdam : Elsevier
    Journal of Human Evolution 15 (1986), S. 325-332 
    Details
    ISSN: 0047-2484
    Keywords: Australopithecus ; Early hominid ; Garusi ; Hadar ; premaxilla
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Biology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1016/S0047-2484(86)80015-X
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Orientation ability of thermotropic liquid crystalline comb-like siloxane polymers as studied by NMR spectroscopy (1991)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 42 (1991), S. 140-144 
    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: Nematisch und smektisch orientierte Siloxanseitenkettenpolymere wurden mit der FT-1H-NMR-Methode untersucht, um Informationen über einen makroskopischen Ordnungsparameter bei Variation des mesogenen Kettenlängenendes zu erhalten. Die Protonenspektren spiegeln direkt die Rolle des Spacers im Orientierungsprozeß des flexiblen Seitenkettenpolymers wider.
    Notes: Nematically and smectically ordered samples of comb-like siloxane polymers were studied by FT-1H-NMR method to get information about the macroscopic order parameter varying the chain-end length of the mesogenic side group. The proton spectra (line shape, splitting) reflect directly the role of the spacer in the ordering process of the comb-like polymers.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1991.010420402
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Quantum chemical calculation (of conformations) and NMR spectrum interpretation (1984)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 35 (1984), S. 244-246 
    Details
    ISSN: 0323-7648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1984.010350312
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Beobachtungen zum Orientierungsverhalten lyotroper polymerer Flüssigkristalle im Magnetfeld (1989)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 40 (1989), S. 564-568 
    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: Liquid crystalline solutions of poly (γ-benzyl-L-glutamate) in methylene dichloride were investigated with regard to the interaction between oriented molecules and external magnetic fields. Using the 1H-NMR method it is possible to observe the influence of the magnetic field on the preferred direction of ordered helix-like macromolecules. The time of this director changing process could be measured. It depends on the molar mass and on the sample volume. A better macroscopic orientation is reached in the reorientation process.
    Notes: Der flüssigkristalline Zustand von Poly(γ-benzyl-L-glutamat)-Lösungen wird hinsichtlich der Wechselwirkung zwischen orientierten Molekülen und anliegendem äußeren Magnetfeld untersucht. Ein Experiment wird vorgestellt, in dessen Ergebnis die Rückorientierungszeit der makroskopischen Orientierung der Probe bestimmt wird. Die Molmasse des Polymers und der Probendurchmesser beeinflussen die Rückorientierungszeit. Im Prozeß des Rückorientierens wird eine einheitlichere Orientierung erreicht.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1989.010400903
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    EPR studies during radical polymerization in the liquid state. Review (1981)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 32 (1981), S. 491-511 
    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: Die Möglichkeiten und Grenzen, EPR-spektroskopisch tiefergehende Erkenntnisse über die Elementarprozesse der Radikalbildung und der Polymerisation zu gewinnen, werden vorgestellt. Die Darstellung erfolgt hauptsächlich an Hand von Messungen an kurzlebigen Radikalen, die in der Startphase der Vinylpolymerisation und -copolymerisation und während der Photolyse von Maleinsäureanhydrid-Lösungen auftreten. Berichtet wird über chemische und sterische Radikalstrukturen, über innermolekulare und Gesamt-Bewegung freier Radikale, über zwischenmolekulare Wechselwirkungen in Polymerisationslösungen, über die Erforschung von Reaktionsmechanismen und von Vorgängen im Elektronenspinsystem (CIDEP) mittels stationärer und zeitaufgelöster EPR sowie über die Ermittlung von Reaktionsgeschwindigkeits-Konstanten.
    Notes: This paper deals with the possibilities and limitations of obtaining data on the elementary processes of radical formation and polymerization. As examples were especially discussed measurements carried out during the initial reactions of vinyl polymerization and copolymerization and during the photolysis of maleic anhydride solutions. Chemical and steric radical structures, internal and external motion of free radicals, intermolecular interactions in polymerizing solutions, the investigation of reaction mechanisms and of processes in the electron spin system (CIDEP) by stationary and time-resolved EPR as well as the determination of rate constants of chemical reactions are reported.
    Additional Material: 18 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1981.010320901
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    13C-NMR-Untersuchungen an Styren-Maleinsäureanhydrid-CopolymerenVortrag auf dem Mikrosymposium „Radikalische Polymerisation“, März 1980 in Leipzig. (1981)
    Weinheim : Wiley-Blackwell
    Acta Polymerica 32 (1981), S. 277-280 
    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: Based on 13C NMR investigations the microstructure of the polymer chain is shown to be controlled by varying the monomer composition. The copolymerization of maleic anhydride with styrene in excess results in distinct deviations from the alternating structure.
    Notes: Anhand von 13C-NMR-Messungen wird gezeigt, wie durch Variation der Monomerzusammensetzung die Mikrostruktur der makromolekularen Kette vorbestimmt werden kann. Bei unter Überschuß von Styren ablaufender Copolymerisation mit MSA entstehen sicher nachweisbare Abweichungen von der alternierenden Struktur.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/actp.1981.010320509
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...