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  • 1985-1989  (5)
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Publisher
Years
Year
  • 1
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 142 (1986), S. 123-135 
    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: Es wurden lineare p-dimethylaminobenzoylierte Polystyrole hergestellt. Zwei Wege sind dabei verfolgt worden: Einer durch Bildung von Polystyrollithium und der andere durch Polystyrolamidbildung. Mit dem ersten Weg, Poly-p-iodstyrol → Poly-p-lithiumstyrol und Reaktionen des Polylithiumstyrols mit Methyl-4-N,N-dimethylaminobenzoat, wurde immer ein vernetztes Polymeres erhalten, das Hydroxygruppen, und in einigen Fällen  -  in Gegenwart eines Überschusses von Methyl-4-N,N-dimethylaminobenzoat und niedrigen Temperaturen  -  auch Dimethylaminobenzoylgruppen enthielt. Der zweite Weg, Polystyrolamidbildung und nachfolgende Reaktion dieser linear funktionellen Polystyrole mit POCl3 und Dimethylanilin, führte zu einem linearen p-dimethylaminobenzoylierten Polystyrol.Ausgehend von Cumol unter Anwendung derselben Prozedur wie für Polystyrol beschrieben, wurden N-Phenyl-p-isopropylbenzamid und 4-Isopropyl-4′-N-N-dimethylaminobenzophenon als Modellverbindungen erhalten. Beide Modellverbindungen und die funktionellen Polystyrole wurden mit IR, UV, 1H-NMR und Massenspektroskopie sowie Molekulargewichtsbestimmungen charakterisiert. Aus Polystyrolamid wurden auch Polystyrolester und Polystyrolsäure erhalten.
    Notes: Linear p-dimethylaminobenzoylated polystyrenes have been synthesized. Two routes, one of them by polystyrene lithiation and the other one by polystyrene-amide formation, have been followed. With the first route, poly-p-iodostyrene → poly-p-lithio-styrene and reaction of lithiated polystyrene with methyl-4-N,N-dimethyl-aminobenzoate, a crosslinked polymer was always obtained which contained hydroxylic groups and in some cases, in the presence of an excess of methyl-4-N,N-dimethylaminobenzoate and low temperatures, dimethylaminobenzoyl groups. The second route, polystyrene-amide formation and subsequent reaction of this linear functionalized polystyrene with POCl3 and dimethyl-aniline, yielded a linear p-dimethylaminobenzoylated polystyrene. Starting with cumene and following the same procedure described for the polystyrene, the model compounds N-phenyl-p-isopropylbenzamide and 4-isopropyl-4′-N,N-dimethylaminobenzophenone were also obtained. Both model compounds and functionalized polystyrenes were characterized by IR, UV, 1H-NMR and mass spectroscopy as well as molecular weight determinations. From polystyrene-amide, polystyrene-ester and polystyrene-acid were also obtained.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0173-2803
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The grafting of o- and p-benzyloxybenzaldehyde onto linear chloromethylated polystyrene is described. The resulting soluble polymeric photosensitizers and their model compounds, o- and p-(p-isopropylbenzyloxy)benzaldehyde, were tested as triplet energy donors against trans-stilbene in benzene solution. Irradiation of the ortho-compounds gives rise to a transformation which has been tentatively attributed to an intramolecular photocyclization. Stern-Volmer constants for the photostable para-compounds were determined. Results for both types of compounds show that the sensitizer efficiency diminishes when it is bound to the polymer.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The initial rate of the polymerization of methyl acrylate photoinitiated by 4-dimethylamino-4′-isopropylbenzophenone (2) varies linearly with monomer concentration and the square-root of light intensity. For small absorbances, the initial polymerization rate, Rp, varies linearly with the square-root of the photoinitiator concentration. For high absorbance values, Rp is independent of the photoinitiator concentration in a well-stirred system and decreases as the photoinitiator concentration increases in an unstirred system. This marked differences between the polymerization kinetics in well-stirred and unstirred systems is discussed. The ratio of the propagation rate constant and the square-root of the termination rate constant, kp/kt1/2, and the quantum yield of photoinitiation were determined and related to the results previously obtained in a study on the photoreactivity of 2.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 5
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The photodehydrochlorination of four poly(vinyl chloride) (PVC) samples of different tacticities, as studied previously, was compared with that of a PVC sample after being modified to various degrees by nucleophilic substitution with sodium benzenethiolate (NaBT). In order to separate the influence of substituted structures from that of the chromophoric group grafted onto the polymer, a series of PVC mixtures with sec-butyl phenyl sulfide (BPT), of compositions similar to those of modified polymers was also studied. The evolution of HCl was found to be a linear function of the absorbed dose in all cases. The quantum yield of dehydrochlorination, ΦHCl, as obtained from the slopes, appeared to decrease with the isotactic content. The results suggest specific isotactic triads to be markedly reponsible for the photodehydrochlorination, which would account for a mechanism based on the occurrence of chlorines of low dissociation energy at such triads.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
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