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  • 1
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The copolymerization of acrylamide with acrylic acid by use of 4,4′-azo-bis-(4-cyanovaleryl)-bis-(m-chlorobenzoyl) diperoxide as initiator was studied. The thermolysis or photolysis of the mentioned initiator was studied. The thermolysis or photolysis of the mentioned initiator was used to prepare polystyrene with final peroxidic groups, which was further reacted with acrylamide to yield poly(styrene-acrylamide).
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  • 2
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The paper is concerned with the polymerization of methyl methacrylate initiated with invertase and copper(II) ion in water. The effect of invertase amount, CuCl2·2H2O amount and temperature on conversion and molecular weight of the formed polymer are presented. The overall activation energy was estimated to be 63.91 kJ/mole.
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  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Polymer bulletin 12 (1984), S. 369-374 
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The immobilization of invertase on carboxymethyl cellulose acid chloride and the factors influencing the reaction (enzyme/support ratio, duration and pH) are studied. The activity of both coupled and free enzymes varies with temperature and pH of the incubation reaction. The values of the Michaelis-Menten constant are higher for the immobilized enzyme.
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  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Polymer bulletin 12 (1984), S. 419-425 
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary Acrylamide was polymerized by both thermolysis and photolysis of the 4,4′-azo-bis-(4-cyanovaleryl)-bis-(m-chlorobenzoyl) diperoxide as initiator. The molecular weight and the conversion depend on polymerization duration and initiator concentration. The sequential character of the initiator was proved by the two stage polymerization of acrylamide when the obtained molecular weights were twice as compared to those of the one stage process.
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  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Polymer bulletin 16 (1986), S. 319-325 
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary In the present paper the coupling of ampicilline on (chlorocarbonylmethyl)cellulose is studied. The reaction is influenced by the drug/support mole ratio, duration and solvent volume (DMSO). The dependence of the coupling yield on the above — mentioned parameters is described fairly by a regression equation of the second order whose coefficients were settled by the multiple regression method. The obtained products are polymer drugs with retard antimicrobial action.
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  • 6
    ISSN: 1436-2449
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Summary The polymerization of methyl methacrylate initiated by a system consisting of invertase, ferric chloride and water was investigated at room temperature. Second order, central, composite, rotatable experimental design was used in order to perform the work.
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  • 7
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Biotechnology and Bioengineering 34 (1989), S. 283-290 
    ISSN: 0006-3592
    Keywords: Chemistry ; Biochemistry and Biotechnology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Process Engineering, Biotechnology, Nutrition Technology
    Notes: This article reports on the reaction of urease immobilization through its covalent bonding on carboxymethylcellulose. The reaction is activated by dicyclohexylcarbodiimide. The coupling reaction is influenced by the enzyme-support and activator-support ratios, as well as by duration. Starting from a rotating, composed experimental program of the second order, the function correlating the activity of the immobilized enzyme with the reaction parameters is established. Immobilized urease exhibits thermal stability higher than that of free enzyme, regarding both pH and the inhibiting action of some metal ions or organic substances. The stability over time of the immobilized urease is high, its enzymatic activity being maintained at over 85% of the initial value three months after synthesis.
    Additional Material: 13 Ill.
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  • 8
    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 wurde die Synthese von 5,5′-Azo-bis-(5-cyanocaproyl)-benzoyldiperoxyd durchgeführt, wobei man von der 5,5′-Azo-bis-(5-cyanohexanon)-säure ausging; diese wurde ihrerseits aus 5-Ketocapronsäure, Hydrazinsulfat und Natriumcyanid bereitet.Die 5,5′-Azo-bis-(5-cyanohexanon)-säure wird in das Säurechlorid überführt und dieses mit Perbenzoesäure kondensiert. Die Strukturen der Zwischenprodukte und des Reaktionsproduktes wurden mittels Elementaranalyse, IR- und NMR-Spektroskopie ermittelt.Um den bifunktionellen Charakter des synthetisierten Initiators festzustellen, wurden die Thermolyse-Konstanten der Azo- und Peroxydgruppen, die Aktivierungsenergien und die Halbwertszeiten bestimmt. Beim Virgleich der kinetischen mit den bei der Thermolyse erhaltenen Daten wurde beim 4,4′-Azo-bis-(4-cyanovaleryl)-ben-zoyldiperoxyd eine Verstärkung des bifunktionellen Charakters und der Reaktionsgeschwindigkeit durch die Verlängerung des Radikals, welches die Azo- und Peroxydgruppen verbindet, festgestellt.
    Notes: 5,5′-Azo-bis-(5-cyanocaproyl)-benzoyl diperoxide was synthesized starting from 5,5′-azo-bis-(5-cyanohexanoic) acid, obtained in its turn from 5-keto-hexanoic acid, hydrazine sulphate and sodium cyanide.5,5′-Azo-bis-(5-cyanohexanoic) acid was then converted into acid chloride and condensed with perbenzoic acid. The structures of intermediates and of the product were elucidated by means of elemental analysis and IR and NMR spectral measurements.In order to settle the bifunctional character of the synthesized initiator the thermolysis rate constants for azo and peroxy groups, energies of activation and half-life times were settled. By comparing the kinetic data with those obtained in 4,4′-azo-bis-(4-cyanovaleryl)-benzoyl diperoxide thermolysis the decomposition rate was found to increase and the bifunctional character to enhance with increasing length of the radical connecting the azo and peroxy groups.
    Additional Material: 5 Ill.
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  • 9
    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 wurde die durch Schwingmahlung angeregte mechanochemische Polymerisation des ternären Systems Acrylnitril/Vinylacetat/α-Methylstyrol untersucht. Für die Reakionsgeschwindigkeit wird ein allgemeiner Ausdruck vorgeschlagen: \documentclass{article}\pagestyle{empty}\begin{document}$${\rm v = k [AN]}^{\rm a}\ {\rm [VA]}^{\rm b}\ {\rm [MS]}^{\rm c} $$\end{document} Die Kinetik der Reaktion wurde durch gaschromatographische Bestimmung des nichtreagierten Monomeren bestimmt. Die partiellen Reaktionsordnungen - bezogen auf jedes einzelne Monomere - hatten einheitliche Werte. Bestimmt wurden diese aus den Zeit-Umsatzkurven von sieben ternären Gemischen mit verschiedenen Monomeranteilen. Die bei drei Temperaturen erhaltenen Reaktionskonstanten gestatteten die Berechnung der Aktivierungsenergie (18.82 kJ mol-1). Die Kleinheit dieses Wertes weist darauf hin, daß der Anteil der thermischen Energie bei einer solchen Synthese unbedeutend ist.
    Notes: The kinetics of mechanochemical copolymerization of the ternary system based on acrylonitrile, vinyl acetate, and α-methyl styrene, by vibratory milling activation was studied. A general relation for expressing the reaction rate is proposed as follows: \documentclass{article}\pagestyle{empty}\begin{document}$${\rm v = k [AN]}^{\rm a}\ {\rm [VA]}^{\rm b}\ {\rm [MS]}^{\rm c} $$\end{document} Kinetics has been followed by measuring the amount of unreacted monomer by gas chromatography. Partial reaction orders - related to each comonomer, had almost unitary values, being determined from the conversion-time curves for 7 ternary systems with different comonomer ratios. The values of the reaction rate constant - taken for three temperatures - permitted the computation of the activation energy (18.82 kJ mol-1), such a low value showing that the contribution of the thermal energy in this type of synthesis is unsignificant.
    Additional Material: 9 Ill.
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  • 10
    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 Polymerisation von Styrol wurde in Gegenwart des Initiators 4,4′-Azo-bis-(4-cyanovaleryl)-bis-(m-chlor-benzoyl)-diperoxid durchgeführt, dessen Aufspaltung thermisch (60°C) und photochemisch (λ = 366 nm) erreicht wurde. Der so erhaltene Polystyrol-Initiator enthält peroxidische Endgruppen, die imstande sind, einen Block-Copolymerisationsprozeß in der zweiten Stufe auszulösen. Das Molekularge-wicht des Polystyrols hängt von der Zeit, der Temperatur und der Konzentration des Initiators ab.
    Notes: The polymerization of styrene was carried out in the presence of 4,4′-azo-bis-(4-cyanovaleryl)-bis-(m-chlorobenzoyl)-diperoxide as initiator. The scission of the initiator was achieved both thermally (60°C) and photochemically (λ = 366 nm). The initiator polystyrene thus obtained contains peroxy end groups capable of initiating a block copolymerization process in the second stage. The molecular weight of polystyrene depends on time, temperature, and initiator concentration.
    Additional Material: 6 Ill.
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