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  • Chemistry  (2)
  • 1970-1974  (2)
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  • 1
    Electronic Resource
    Electronic Resource
    Transesterification of poly(methyl acrylate) with optically active alcoholsDedicated to Professor Dr. ICHIRO SAKURADA on his 70th birthday (1974)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 175 (1974), S. 7-16 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Umesterungen von ataktischem und isotaktischem Poly(methylacrylat) mit optisch aktiven Alkoholen wie (S)-2-Methylbutanol, D-Borneol und L-Menthol wurden in Toluol bei 100°C mit p-Toluolsulfonsäure als Katalysator durchgeführt, um optisch aktive Polymere zu erhalten. Außerdem wurde die Beziehung zwischen Konformation und optischem Verhalten des umgeesterten Poly(methylacrylats) untersucht. Die spezifische Drehung des umgeesterten ataktischen Poly(methylacrylats) wächst linear mit der Zunahme eingeführter optisch aktiver Gruppen in die Seitenkette im Gegensatz zu derjenigen des isotaktischen Poly(methylacrylats), die nicht linear mit der Zunahme asymmetrischer Gruppen ansteigt. Da die spezifischen Drehungen der umgeesterten Polymere von diesen Taktizitäten abhängen, wurde gefolgert, daß die optische Aktivität nicht nur durch die asymmetrischen Gruppen in der Seitenkette, sondern auch durch molekulare Asymmetrie in der Hauptkette verursacht wird.
    Notes: Transesterifications of atactic and isotactic poly(methyl acrylate) with optically active alcohols such as (S)-2-methyl-butanol, D-borneol and L-menthol were carried out in toluene at 100°C using p-toluenesulfonic acid as catalyst to obtain optically active polymers. In addition a relationship between the conformation and the optical behaviour of the transesterified poly(methyl acrylate) was investigated. The specific rotation of the transesterified atactic poly(methyl acrylate) increased linearly with increasing introduced optically active groups at the lateral chain, in contrast to that of the isotactic poly(methyl acrylate) which increased nonlinearly with increasing introduced asymmetric groups. Since the specific rotations of the transesterified polymers depend on these tacticities the conclusion was drawn that the optical activity is caused not only by the asymmetric group in the lateral chain but also by molecular dissymmetry in the principal chain.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1974.021750102
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  • 2
    Electronic Resource
    Electronic Resource
    Asymmetric oxidation of poly(vinyl sulfides) with percamphoric acid, aspergillus niger, and penicillium notatum (1971)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 15 (1971), S. 1869-1880 
    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: The asymmetric oxidation of poly(phenylvinyl sulfide) (poly-Ph VS) and poly(t-butylvinyl sulfide) (poly-t-BuVS) was carried out with optically active percamphoric acid, and the optically active polysulfoxides were obtained. The values of the specific rotation for the oxidation products of poly-PhVS and poly-t-BuVS were + 1.0 (having 56% of sulfoxide unit contents) and +9.1 (49%), respectively. The specific rotation of the product increased with increasing the contents of sulfoxide units. The optical rotatory dispersion curves of the oxidation products of poly-PhVS and poly-t-BuVS were positive curves and were found to fit the simple Drude equation. The λc values of the oxidation products (poly-PhVS, 271 mμ; poly-t-BuVS, 212 mμ) suggested that the chromophore which caused optically activity was the sulfoxide group. Similarly, the asymmetric oxidation of t-BuVS-MMA copolymer, t-BuVS-styrene copolymer, and PhVS-MMA copolymer was carried out, and the optically active copolysulfoxides were obtained. Furthermore, the biosynthetic oxidation of poly-PhVS and PhVS-maleic anhydride copolymer treated with aqueous KOH was carried out using Aspergillus niger or Penicillium notatum in Czapeck solution, and the optically active polymers were obtained.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1971.070150806
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