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  • 1
    Digitale Medien
    Digitale Medien
    Statistical models in the study of stereospecific polymerization (1969)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-2: Polymer Physics 7 (1969), S. 763-773 
    Details
    ISSN: 0449-2978
    Schlagwort(e): Physics ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Triad tacticity data obtained by NMR analysis have previously been interpreted in terms of two basic statistical models in order to elucidate the stereospecific polymerization mechanism. In this paper the characteristics of these two basic models for stereospecific polymerization, the enantiomorphic-sites (EMS) model, and the polymer-end control (PEC) model, are examined and compared. The tacticity values accessible to the two-parameter EMS model, which includes the influence of the chain end unit, are shown to be highly restricted. Only about 20% of the isotacticity versus syndiotacticity plot is accessible to this model. To this extent the consistency of a set of triad tacticity data with the model can be tested. No such tacticity limits are exhibited by the two-parameter PEC model, which includes the influence of the penultimate unit. Any set of tacticity values which can be interpreted in terms of the two-parameter EMS model can also be interpreted in terms of the two-parameter PEC model.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pol.1969.160070502
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  • 2
    Digitale Medien
    Digitale Medien
    Quaternary anilinium salt as an initiator for vinyl polymerization (1955)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 15 (1955), S. 594-595 
    Details
    ISSN: 0022-3832
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pol.1955.120158027
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  • 3
    Digitale Medien
    Digitale Medien
    Catalytic reactivity of organometallic, compounds for olefin polymerization. I. Diethylcadmium and other related compounds (1959)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 30 (1959), S. 109-122 
    Details
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Diäthylcadmium löst in Gegenwart einiger Sauerstoffverbindungen die Vinylpolymerisation aus. Die Copolymerisation von Styrol und Methacrylsäuremethylester mit Diäthylcadmium liefert Copolymere mit den gleichen Einbauverhältnissen wie im Fall einertypischen Radikalkettencopolymerisation. Dieses Ergebnis bedeutet, daß die Wachstumsreaktion der hier beschriebenen Polymerisation nach einem Radikalmechanismus verläuft.Benzoehinon und Hydrochinon haben, wenn sie in geeigneten Mengen verwendet werden, eine beschleunigende Wirkung auf die Polymerisation. Ein möglicher Mechanismus für die Wirkung des Chinons und Hydrochinons wird aufgezeigt. Vergleichende Polymerisationsversuche mit den Äthylderivaten des Zink, Aluminium und Antimon zeigen, daß auch sie nach einem Radikalmechanismus verlaufen.Schließlich wird, in Analogie zum ZIEGLER-Katalysator, das Verhalten eines Gemisches von Diäthylcadmium und Titantetrachlorid im Molverhältnis 4 : 1 an verschiedenen Vinylmonomeren untersucht.
    Notizen: Diethylcadmium induces vinyl polymerization in the presence of some oxygen compounds. Copolymerization between styrene and methyl methacrylate using diethylcadmium resulted in the formation of copolymers having the same composition as those from the typical radical copolymerization. These results suggest at least the propagation stage of the present polymerization to proceed according to the radical mechanism. However, benzoquinone or hydroquinone in an appropriate quantity was found to be an effective co-catalyst toward this polymerization. A possible mechanism for this is advanced. Comparative study of polymerizations with ethyl derivatives of zinc, aluminium and antimony has revealed that these polymerizations are also radical type in character. Finally, in connection with the ZIEGLER-catalyst, the behavior of the mixture of diethylcadmium and titanium tetrachloride (4 : 1 in mole ratio) toward various vinyl monomers is exatnined.
    Zusätzliches Material: 2 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/macp.1959.020300108
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  • 4
    Digitale Medien
    Digitale Medien
    Co-catalytic action of quinones and phenols in methyl methacrylate polymerization by diethylcadmium (1958)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 31 (1958), S. 247-249 
    Details
    ISSN: 0022-3832
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Zusätzliches Material: 2 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pol.1958.1203112251
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  • 5
    Digitale Medien
    Digitale Medien
    Quaternary ammonium salt as initiator for vinyl polymerization (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 36 (1959), S. 407-420 
    Details
    ISSN: 0022-3832
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: Binary mixtures of amines and alkyl (or aralkyl) chlorides were used as the initiators for the polymerizations of several acrylic monomers and styrene. A parallelism was found between the catalytic actions of the mixtures and their quaternary salt formations. Comparative experiments showed that the preformed quaternary ammonium salts were superior catalysts to the corresponding binary mixtures. The inhibitory action of hydroquinone on the polymerization and the composition of a copolymer of methyl methacrylate and styrene suggested that the vinyl polymerizations initiated by ammonium salts were free radical reactions. An equimolar mixture of benzyl chloride and N,N-dimethylaniline gave, when refluxed for ten hours, N-methyl-N-benzylaniline and N,N-dibenzylaniline. Thus, it was suggested that the binary mixtures would first form the ammonium salts, followed by decomposition to give a radical which initiated the radical polymerizations of vinyl monomers.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pol.1959.1203613034
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  • 6
    Digitale Medien
    Digitale Medien
    Molecular orbital considerations on the reactivities of vinyl compounds. II. Ionic polymerizability (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 40 (1959), S. 499-510 
    Details
    ISSN: 0022-3832
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: The β-carbon localization energies Lβ+ and Lβ- for electrophilic and nucleophilic additions to vinyl compounds, respectively, were calculated according to the simple LCAO MO method and were compared with the experimental results so far reported on the ionic polymerizability of these compounds. The larger the cationic (or anionic) polymerizability of a monomer, the smaller was the value of Lβ+ (or Lβ-) for it. It was also verified in terms of localization energies that the vinyl monomers which are not amenable to radical polymerization tend to polymerize more easily by either of the two ionic mechanisms. By applying Jaffé's first order perturbation method, Lβ+ and Lβ- of each monomer were expressed as functions of the Coulomb integral parameters of the heteroatoms involved. Although the values of Lβ+ and Lβ- did not agree perfectly with the direct results obtained from secular equations, the discrepancy in both cases could be minimized when each of the Coulomb integral parameters employed in the perturbation approximation was empirically taken as 0.6 times as large as that used in the direct variation calculation. The procedure was successfully applied to the interpretation of the substituent effect on the cationic polymerizability of styrene.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pol.1959.1204013718
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  • 7
    Digitale Medien
    Digitale Medien
    Molecular orbital considerations on the reactivities of vinyl compounds. III. Polarographic reduction (1959)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 40 (1959), S. 511-519 
    Details
    ISSN: 0022-3832
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Notizen: The polarographic half-wave reduction potentials E1/2 of several vinyl (including vinylidene) monomers were measured and were discussed on the basis of the molecular orbital theory. The current-voltage curves were determined in a 0.05 M solution of tetra-n-butylammonium iodide in the mixture of dioxane and water (3:1 by volume). The values of E1/2 were read against the saturated calomel electrode. It was found that E1/2 is correlated with xiv by E1/2 = 2.33 xiv-0.80, where xiv stands for the root of the MO secular equation for the π-electronic system of the vinyl monomer corresponding to the lowest vacant level. Some of the monomers could not be reduced in the range of the applied potential less negative than - 3.0 volt vs. SCE, which was reasonably explained by their relatively large values of -xiv. It was suggested that the polarographic reducibility of vinyl monomers is roughly parallel to their anionic polymerizability. Furthermore, the lowest vacant π-orbital energies of vinyl compounds were calculated according to the first order perturbation method. The results obtained thus were in good accordance with those calculated directly from the secular equations. It was also shown that the first ionization potentials of vinyl compounds were roughly related to their highest occupied π-electronic energies.
    Zusätzliches Material: 1 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pol.1959.1204013719
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  • 8
    Digitale Medien
    Digitale Medien
    Ionic properties of the triethylaluminum and stannic cloride system as stereospecific polymerization catalyst for vinyl isobutyl etherPresented at the 16th Annual Meeting of the Chemical Society of Japan (Tokyo, April, 1963). (1964)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 76 (1964), S. 209-229 
    Details
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Die Polymerisation des Vinylisobutyläthers wurde mit Aluminiumtriäthyl und Zinntetrachlorid als Katalysatorsystem untersucht. Der mit äquimolekularen Mengen von Aluminiumtriäthyl und Zinntetrachlorid erhaltene Polyvinylisobutyläther zeigte die höchste Isotaktizität.Aus Messungen der Reaktionswärme von Aluminiumtriäthyl mit Zinntetrachlorid und aus der Analyse der bei der Hydrolyse dieses katalytischen Systems entwickelten Gase geht hervor, daß aus Aluminiumtriäthyl und Zinntetrachlorid sich Aluminiumchlorid und Triäthylzinnchlorid bilden. Kryoskopische Messungen und NMR-Untersuchungen zeigen klar, daß Triäthylzinnchlorid und Aluminiumchlorid in Benzol assoziiert sind. Überdies zeigt das 1:1-Gemisch von Aluminiumtriäthyl und Zinntetrachlorid eine bemerkenswert hohe Leitfähigkeit sogar in unpolaren Lösungsmitteln wie Toluol. Bei der Elektrolyse dieses katalytischen Systems in Toluol wurden sowohl Aluminium- als auch Zinn-Verbin-dungen an den Elektroden abgeschieden. Daraus wurde auf die Bildung multipler Ionen wie \documentclass{article}\pagestyle{empty}\begin{document}$$ ({\rm Et}_{\rm 3} {\rm Sn}^ + \cdots - {\rm AlCl}_4 )_{\rm n} {\rm Et}_3 {\rm Sn}^ + {\rm and }( - {\rm AlCl}_4 \cdots {\rm Et}_3 {\rm Sn}^ + )_{\rm n} - {\rm AlCl}_4, $$\end{document} geschlossen, die in Übereinstimmung stehen mit dem Mehrzentrenkatalysator der stereo-regulären Polymerisation, den wir früher vorschlugen.
    Notizen: Polymerization of vinyl isobutyl ether was investigated with the catalytic system triethylaluminum and stannic chloride. The poly(vinyl isobutyl ether) obtained with an equimolar mixture of triethylaluminum and stannic chloride possessed the highest isotacticity.Measurement of the heat of reaction between triethylaluminum and stannic chloride and determination of the gas evolved on hydrolysis of this catalytic system showed that the reaction product of an equimolar amount of triethylaluminum and stannic chloride is an equimolar mixture of aluminum chloride and triethyltin chloride. Cryoscopic measurements and NMR studies indicated definitely that aluminum chloride and triethyltin chloride are highly associated in benzene. Furthermore, the 1:1-mixture of triethylaluminum and stannic chloride exhibited remarkably high electric conductivity even in a non-polar solvent like toluene. In the electrolysis of this catalytic system in toluene, both aluminum and tin compounds were deposited at both electrodes.These results lead us to the concept of the formation of multiple ions such as \documentclass{article}\pagestyle{empty}\begin{document}$$ ({\rm Et}_{\rm 3} {\rm Sn}^ + \cdots - {\rm AlCl}_4 )_{\rm n} {\rm Et}_3 {\rm Sn}^ + {\rm and }( - {\rm AlCl}_4 \cdots {\rm Et}_3 {\rm Sn}^ + )_{\rm n} - {\rm AlCl}_4, $$\end{document} in favor of the hypothesis of the multi-center catalyst in stereoregular polymerization, previously proposed by us.
    Zusätzliches Material: 11 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/macp.1964.020760118
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  • 9
    Digitale Medien
    Digitale Medien
    Studies on the mechanism of the stereospecific polymerization. Asymmetric-induction polymerization of benzofuran by use of optically active organo-stannic compounds (1965)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 83 (1965), S. 234-243 
    Details
    ISSN: 0025-116X
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Beschreibung / Inhaltsverzeichnis: Im Zusammenhang mit unseren früheren Arbeiten über die Polymerisation von Vinyläthern mit dem System Aluminiumtriäthyl/Zinnchlorid untersuchten wir die Wirkung verschiedener Äther auf die Ioneneigenschaften dieses binären Katalysators. Darüber hinaus wurde Benzofuran mit Hilfe ternärer Systeme, die verschiedene asymmetrische Verbindungen enthielten, polymerisiert. ( - )Menthoxytriäthylzinn ergab Polybenzofuran mit hoher optischer Aktivität.Aus elementaranalytischen Daten und aus Messungen der elektrischen Leitfähigkeit des Katalysatorsystems sowie aus den Resultaten der Polymerisationsversuche wird auf jene Eigenschaften geschlossen, die die asymmetrische Polymerisation bewirken.
    Notizen: In connection with our previous study on the system triethylaluminum/stannic chloride as a catalyst for the polymerization of vinyl ethers, the effects of ether compounds on the ionic properties of the binary system were investigated. Furthermore, benzofuran was polymerized with the aid of the ternary systems involving various asymmetric compounds. ( - )Menthoxytriethyltin was found to be effective as third component for preparation of polybenzofuran with high optical activity.From data of the elemental analyses and the electric conductivity measurements of the catalytic system as well as the polymerization results the properties of the counter-ion in the asymmetric polymerization are discussed.
    Zusätzliches Material: 3 Ill.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/macp.1965.020830121
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  • 10
    Digitale Medien
    Digitale Medien
    Diethylcadmium as an initiator for vinyl polymerization (1958)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 28 (1958), S. 234-235 
    Details
    ISSN: 0022-3832
    Schlagwort(e): Chemistry ; Polymer and Materials Science
    Quelle: Wiley InterScience Backfile Collection 1832-2000
    Thema: Chemie und Pharmazie , Physik
    Zusätzliches Material: 1 Tab.
    Materialart: Digitale Medien
    URL: http://dx.doi.org/10.1002/pol.1958.1202811627
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