Library

feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Springer
    Colloid & polymer science 256 (1978), S. 300-300 
    ISSN: 1435-1536
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 37 (1959), S. 131-145 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It has been found that the polymerization of acrylonitrile dissolved in water proceeds easily in the presence of hydrogen peroxide and iron(III) salts. The kinetic investigation of this reaction shows that it is second order with respect to the monomer. The rate of reaction invreases with the concentration of hydrogen peroxide and of iron(III) salt but it decreases with an increase in the concentration of hydrogen ions. The average molecular weight of the formed polymer was determined by viscosity measurements. The degree of polymerisation increases with the concentration of the monomer and hydrogen ions, but decreases with an increase in the concentration of hydrogen peroxide and iron(III) salt. The reaction is inhibited by dissolved gaseous oxygen. Under otherwise similar conditions, the rate of the decomposition of hydrogen peroxide is considerably decreased in the presence of the acrylonitrile compared with its catalytic decomposition by iron(III) salts without acrylonitrile present. The amount of hydrogen peroxide decompsed on the average is more than two molecules per molecule of the formed polymer. The experimental data are briefly discussed in relation to a plausible reaction mechanism.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 12 (1974), S. 1323-1325 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 61 (1962), S. 113-126 
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Vinyl acetate has been polymerized in buffered aqueous solution at 40°C., with potassium peroxydisulfate as initiator, a dilatometric method being used to follow the reaction. Without the addition of emulsifying agents, a stable suspension of polymer particles is formed resembling a latex obtained in emulsion polymerization. It has been found that the number of latex particles after increasing in the initial stages remains constant for the major part of the reaction. The kinetics of the polymerization conform to the third case of the Smith and Ewart scheme, if it is assumed that the concentration of the monomer in the latex particles remains constant. The calculated propagation constant compares favorably with that for bulk polymerization, while the termination constant compares with that found for highly viscous systems.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 116 (1968), S. 1-7 
    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: Basierend auf der Theorie von HARKINS, SMITH und EWART, welche die Bildung von Latexteilchen während der Ermulsionspolymerisation quantitativ beschreibt, wird der mittlere Polymerisationsgrad abgeleitet. Übertragungsreaktionen werden als nicht vorhanden angenommen. Die mittlere Lebensdauer t̄ der wachsenden Radikale - zu welcher der mittlere Polymerisationsgrad proportional ist - berechnet sich zu \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm \bar t } = {\rm }\frac{{\rm N}}{{\rm \rho }}{\rm }\frac{{3{\rm } + {\rm }2{\rm x } - {\rm e}^{ - 2{\rm x}} }}{{3{\rm } + {\rm }2{\rm x } + {\rm e}^{ - 2{\rm x}} }} $$\end{document} X = ρt/N ist die dimensionslose Veränderliche, die die mittlere Zahl von Radikalen angibt, die pro Latexteilchen in der Zeitspanne t erzeugt wurde. ρ ist die konstante Geschwindigkeit der Radikalbildung und N die Zahl der Latexteilchen in dem Moment des Verschwindens der Emulgatormizellen.
    Notes: The theory of HARKINS, SMITH and EWART, describing the formation of latex particles in the emulsion polymerization system is used, to describe the average degree of polymerization of the formed polymer. Transfer reactions are assumed to be negligible. The average lifetime t̄ of growing polymer radicals - to which the average degree of polymerization is proportional - is found to be \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm \bar t } = {\rm }\frac{{\rm N}}{{\rm \rho }}{\rm }\frac{{3{\rm } + {\rm }2{\rm x } - {\rm e}^{ - 2{\rm x}} }}{{3{\rm } + {\rm }2{\rm x } + {\rm e}^{ - 2{\rm x}} }} $$\end{document} where x = ρt/N is the dimensionless variable representing the average number of radicals created per latex particles by time t. ρ is the constant rate of production of radicals, N is the number of latex particles at the time of disappearance of micelles.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 89 (1965), S. 156-164 
    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: Die SMITH-EWARTsche Theorie, welche die Bildung von Latexteilchen in der Emulsions polymerisation beschreibt, wird durch Ableitung von Gleichungen für die Veränderungs-geschwindigkeit der Mizellen- und Latexteilchenzahl erweitert. In einem gegebenen Falle können diese Gleichungen in geschlossener Form integriert werden, meistens jedoch müssen die Lösungen durch numerische Berechnung gefunden werden. Das Ziel ist die Ableitung von Gleichungen für die Anzahl der Reaktionszentren, ausgedrückt durch experimentelle Veränderliche, welche durch Versuchsbedingungen leicht zu spezifizieren sind - wie die Emulgator- und Initiatorkonzentrationen. Außerdem müssen diese Gleichungen die Aussage enthalten, daß die Zahl der reaktionsfähigen Teilchen zu dem Zeitpunkt, in dem die Teilchenneubildung aufhört, genau die Hälfte der Gesamtteilchenzahl ist. Dieses Ziel ist nur in beschränktem Maße erreicht worden, insofern, als die erstrebten Gleichungen nicht in analytischer Form erhalten werden konnten.
    Notes: The theory of SMITH and EWART, which describes the formation of latex particles in the emulsion polymerization system, is extended by deriving equations for the rate of change of micellar and latex particle numbers. In one case given, these equations can be integrated in closed form, but in most cases, the solutions must be found by numerical computation. The overall aim is to derive an expression for the number of reaction loci which is in terms of variables easily specified by experimental conditions - such as emulsifier and initiator content, and which predicts the number of reacting particles to be one half the total number of particles at the time when particle production ceases. This aim is attained in a limited way only, in so far as the expression sought cannot be furnished in analytic form.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 82 (1965), S. 270-276 
    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: Die spezifischen Brechungsindex-Inkremente für einige Polymer/Lösungsmittel-Systeme wurden mit Hilfe des Interferenzrefraktometers gemessen. Die beschriebene Meßtechnik erlaubt schnelle und genaue Auswertung von dn/dc und eliminiert die Schwierigkeiten, welche normalerweise mit interferometrischen Messungen in organischen Lösungsmitteln verbunden sind.
    Notes: The specific refractive index increments of a number of polymer/solvent systems have been measured by means of an interference refractometer. The technique described permits rapid and precise evaluation of dn/dc, as well as eliminating the difficulties normally associated with interferometric measurements in organic solvents.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 4 (1966), S. 985-995 
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of methyl acrylate in water and in dilute, aqueous, soap solutions, initiated by potassium peroxydisulfate, has been investigated, a dilatometric method being used to follow the conversion. It has been shown that small amounts of an anionic soap increase the rate of reaction while a cationic soap has the reverse effect. The change of molecular weight with conversion has also been examined as well as the effect of the exclusion of oxygen from the system.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...