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  • 1
    Electronic Resource
    Electronic Resource
    Reaction of poly(vinyl alcohol) with diketene (1986)
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 143 (1986), S. 101-113 
    Details
    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 Modifizierung von Polyvinylalkohol mit Diketen, unter Verwendung von tert. Aminen als Katalysatoren, wurde untersucht. Die Struktur der erhaltenen Polymeren wurde durch IR-, 1H-, 13C-NMR-Spektroskopie und chemische Analyse bestimmt. Es wurden Vinylalkohol-Vinylacetoacetat-Copolymere erhalten. Die Reaktionsgeschwindigkeit war jeweils linear abhängig von der Konzentration an Polymerem, Diketen und Pyridin. Die Aktivierungsenergie wurde zu 35,5 kJ/mol (8,5 kcal/mol) bestimmt. Die 13C-NMR-Spektroskopie wurde benutzt, um die Sequenzverteilung in den Copolymeren zu bestimmen; dabei ergab sich eine gewisse Tendenz zur Alternierung von VAL- und VAA-Einheiten in der Polymerkette. Polymere Chelate der Copolymeren mit Kupfer-II-Ionen wurden hergestellt; dabei zeigte sich, daß nicht alle β-Ketoestergruppen an der Komplexbildung beteiligt sind.
    Notes: A study has been made on the modification of poly (vinyl alcohol) with diketene using tertiary amines as catalysts. The structure of the resulting polymers was determined by means of IR, 1H- and 13C-NMR spectroscopy as well as by chemical analysis. Vinyl alcohol-vinyl acetoacetate (VAL-VAA) copolymers were obtained. It has been found a linear dependence of reaction rate on polymer, diketene and pyridine concentrations, respectively. The activation energy was found to be 35.5 kJ/mol (8.5 kcal/mol). 13C-NMR spectroscopy was used for the determination of the sequence distribution in VAL-VAA copolymers. The obtained results show that VAA units have a little alternating tendency in the copolymer chain. Polymeric chelates between VAL-VAA copolymers and cupric ions have been prepared. It is noteworthy that not all the β-keto ester groups in the VAL-VAA copolymers participate in binding cupric ions.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/apmc.1986.051430109
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  • 2
    Electronic Resource
    Electronic Resource
    Modification of amylose with diketene (1986)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 187 (1986), S. 2591-2598 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This work deals with the modification reaction of amylose with diketene using tertiary amines as catalysts. The structure of the resulting polymers was determined by means of IR, 1H and 13C NMR spectroscopy as well as by chemical analysis. A linear dependence of the reaction rate on polymer, diketene and pyridine concentrations was found. The activation energy was found to be 27,2 kJ/mol (6,5 kcal/mol). Polymeric chelates between partially modified amylose and cupric ions (Cu2+) were prepared. However, not all of the β-keto ester groups in the partially modified amylose participate in binding the cupric ions.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1986.021871108
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  • 3
    Electronic Resource
    Electronic Resource
    Study of the distributions of chemical composition and molecular weight in relation to the preparation method of vinyl alcohol/vinyl acetate copolymers (1986)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 187 (1986), S. 1215-1228 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The chemical heterogeneity of two vinyl alcohol/vinyl acetate (VAL-VAC) copolymers prepared by partial acetylation of poly(vinyl alcohol) and by partial alkaline hydrolysis of poly(vinyl acetate), respectively, was studied by cross-fractionation. The used solvent/non-solvent systems were selected on the basis of cloud-point determinations. The chemical composition distribution (CCD) and the molecular weight distribution (MWD) curves were constructed from fractionation data. The observed chemical heterogeneity was correlated with the kinetic parameters of the two different methods used for the preparation of the VAL-VAC copolymers. Thus, squared standard deviation values \documentclass{article}\pagestyle{empty}\begin{document}$\overline {{\rm \sigma }^{2} }$\end{document}= 2,90·10-4 and \documentclass{article}\pagestyle{empty}\begin{document}$\overline {{\rm \sigma }^{2} }$\end{document}= 7,42·10-4 were found for the two VAL-VAC copolymers prepared by acetylation and hydrolysis, respectively. These results are in agreement with theoretical predictions. The cumulative data were fitted by the two-parameters MWD functions of Tung and of Wesslau.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1986.021870518
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  • 4
    Electronic Resource
    Electronic Resource
    Modeling active mass in aerobic sludge digestion (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 28 (1986), S. 1699-1706 
    Details
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: Aerobic digestion of waste-activated sludge was carried out in lab-scale reactors for both batch and semicontinuous flow patterns. The reactors were monitored at three different temperatures: 10, 20, and 30°C. During the course of digestion, significant solubilization of volatile suspended solids was observed, and its effect on the magnitude of kinetic coefficients was examined. Differences in metabolic activity and sludge stabilization were found between batch and semicontinuous flow patterns. An Arrhenius-type relationship was not found to apply to rate constants for the semicontinuous reactors.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/bit.260281113
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  • 5
    Electronic Resource
    Electronic Resource
    Kinetics and mechanism of the decomposition of N-bromoalcoholamines in aqueous solution (1986)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 18 (1986), S. 1249-1258 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The decomposition reactions of N-bromodiethanolamine, N-bromoethylethanolamine, and N-bromomethylethanolamine in aqueous solution have been studied kinetically under various experimental conditions. The results support a proposed reaction mechanism in which the rate controlling step is assumed to be the formation of an imine which is then hydrolyzed to the final decomposition products.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550181104
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