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  • 1960-1964  (5)
  • 1
    Electronic Resource
    Electronic Resource
    Highly stereospecific catalytic systems for the polymerization of α-olefins to isotactic polymers (1961)
    Hoboken, NJ : Wiley-Blackwell
    Journal of Polymer Science 51 (1961), S. 387-398 
    Details
    ISSN: 0022-3832
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The highly stereospecific catalytic systems for the polymerization of α-olefins have been compared. These are obtained starting either from the α, γ, or δ modifications of violet TiCl3 with or without AlCl3 present in solid solution, and from aluminum diethyl monohalides, or from metalloorganic products obtained by reacting two molecules of aluminum monoalkyl dihalide with one molecule of particular electron donor compounds. The catalytic systems considered polymerize propylene, giving rise to crude polymers containing 90 to 100% isotatic propylene (nonextractable in boiling n-heptane) for a wide range of polymerization temperatures. By fractionation of crude polymers prepared with the use of these catalytic systems, highly isotactic polypropylenes, having a melting temperature up to 177°C., have been separated. The results, correlated with those obtained in x-ray determinations of the structure of the modification of TiCl3 used, demonstrate that the stereospecificity of all the catalytic systems examined is independent of the particular type of violet modification (α, γ, or δ), whether or not these contain aluminum as AlCl3 in solid solution. This proves that the single active centers are substantially of the same type; a variation in their number causes only a variation of the overall polymerization rate.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1961.1205115601
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    Paper (German National Licenses)
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  • 2
    Electronic Resource
    Electronic Resource
    Comportement de composés organométalliques de l'aluminium pendant la formation des catalyseurs à base de TiCl3 violet et pendant la polymérisation stéréospécifique des alpha-oléfinesDédié au Prof. GIULIO NATTA à l' occasion de son 60ème Anniversaire (1963)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 61 (1963), S. 116-131 
    Details
    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 Autoren untersuchen das Verhalten bei der stereospezifischen Polymerisation des Propylens mit Systemen, die gebildet werden aus violettem TiCl3 und einem zu den folgenden Klassen gehörenden organometallischen Aluminium-Komplex: Al2R4X2 (R = Alkyl, X = Halogen, OR, SR, SeR, NR2), D·AIR3 (D = LEWISbase), MY·AIR3 oder MY·2AIR3 (MY = Alkali-halogenid), in Abwesenheit oder in Anwesenheit von LEWISbasen, AlRX2 + 1/2Z (X = Halogen, Z = LEWISbase, Alkalihalogenid, „Ionium“-Halogenide). Um die Bildung von polymerisationsaktiven Katalysatorkomplexen zu begünstigen, müssen alle untersuchten Systeme eine genügend hohe Konzentration an AIR3 oder AIR2X-Molekeln in freier, nicht assoziierter Form gelöst enthalten; diese Molekeln sind es, die bei der Bildung der Katalysatorkomplexe aktiv sind. Die Stereospezifität dieser Systeme hängt in erster Linie vom Typ der zur Katalysatorherstellung verwendeten Katalysatorsysteme ab; ihre Aktivität scheint nicht nur von der Natur, sondern auch von der Konzentration dieser freien Molekeln abzuhängen.
    Notes: Les auteurs ont étudié le comportement des systèmes suivants pendant la polymérisation stéréospécifique du propylène. Les systèmes sont préparés à partir de TiCl3 violet et d'un composé organométallique d'aluminium appartenant à l'une des classes: Al2R4X2 (R = alcoyle, X = halogène, OR, SR, SeR, NR2), D·AIR3 (D = base de LEWIS), MY·AIR3 ou MY·2AIR3 (MY = halogénure alcalin), en absence et en présence de base de LEWIS, AlRX2 + 1/2Z (X = halogène, Z = base de LEWIS, halogénure alcalin, halogénure de ‚onium‘). Pour favoriser la formation des complexes catalytiques actifs dans la polymérisation, tous les systèmes qui ont été examinés doivent contenir en solution une concentration suffisante d'espèces AIR3 ou AIR2X à l'état libre et non associé; ce sont ces espèces qui interviennent dans la réaction de formation des complexes catalytiques. La stéréospécificité de ces systèmes dépend principalement du type de composé d'aluminium utilisé pour préparer le système catalytique; leur activité semble dépendre non seulement de la nature, mais aussi de la concentration de telles espèces libres.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1963.020610111
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  • 3
    Electronic Resource
    Electronic Resource
    Dependence of the melting point of isotactic polypropylenes on their molecular weight and degree of stereospecificity of different catalytic systemsDedicated to Prof. Dr. Dr. h. c. K. ZIEGLER on the occasion of his 65th birthday (1964)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 70 (1964), S. 191-205 
    Details
    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: Polymere des Propylens mit hochgradig regelmäßiger isotaktischer Struktur und mit niedrigem Molekulargewicht (bis zu etwa 800) wurden hergestellt. Der Schmelzpunkt, die Röntgenkristallinität, die Löslichkeit in einigen Lösungsmitteln und das Molekulargewicht jeder Polymerfraktion wurden bestimmt.Der Schmelzpunkt steigt mit steigendem Molekulargewicht bis zum Erreichen eines asymptotischen Wertes für Molekulargewichte in der Größenordnung von einigen 10 000.Die erhaltenen Daten wurden benutzt, um zu beweisen, daß die Katalysatorsysteme, die auf TiCl3 und einer der Verbindungen: Al(C2H5)2J, Be(C2H5)2, Al(C2H5)2Br, Al(C2H5)2Cl beruhen, stereospezifischer sind als die, bei denen Al(C2H5)3 verwendet wird.
    Notes: Polymers of propylene having highly regular isotactic structure and low molecular weight (down to about 800) were prepared. The melting point, the X-ray crystallinity, the solubility in some solvents, and the molecular weight of each polymer fraction have been determined.The melting point increases with the increase of the molecular weight until reaching the limiting value for molecular weights of the order of 103.The data have been used in the polymerization of propylene to prove the higher stereospecificity of the catalytic systems based on violet TiCl3 and one of the following compounds: Al(C2H5)2I, Be(C2H5)2, Al(C2H5)2Br, Al(C2H5)2Cl, in comparison with the corresponding systems prepared with Al(C2H5)3.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1964.020700114
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  • 4
    Electronic Resource
    Electronic Resource
    Dismutation of aluminum monoalkyldihalides by the action of complexing substances, and their behaviour in ternary catalytic systems for anionic co-ordinated polymerization processesDedicated to Prof. Dr. Dr. h. c. K. ZIEGLER on the occasion of his 65th birthday (1964)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 70 (1964), S. 206-221 
    Details
    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: Bei der stereospezifischen Polymerisation von Propylen zu isotaktischen Polymeren wurde das Verhalten ternärer Katalysatorsysteme von violettemTiCl3 - Al(C2H5)Cl2-LEWISbase untersucht, und zwar im Bereich LEWISbase/Al von 0-1. Unter den experimentellen Bedingungen sind alle Systeme polymerisationsaktiv, die mit genügend schwachen Basen hergestellt werden, sogar für LEWISbase/Al-Verhältnisse 〉 1. Die Systeme mit starken Basen sind nur etwas aktiv, wenn das Verhältnis LEWISbase/Al 〈 1. Alle aktiven Systeme haben die gleiche Stereospezifität wie die binären Systeme aus violettem TiCl3 und Al(C2H5)2Cl.Dadurch wird die Deutung gestützt, daß Al-alkyldihalogenid zumindest teilweise durch die LEWISbase dismutiert, mit anschließender Bildung von zumindest teilweise nicht komplexem Dialkylhalogenid. Diese Verbindung sollte im monomeren, nicht assoziierten Zustand an der Bildung der Katalysatorkomplexe beteiligt sein. Die Hypothesen stehen im Einklang mit Ergebnissen bei der Polymerisation von Propylen und Butadien mit ähnlichen Systemen.
    Notes: In the stereospecific polymerization of propylene to isotactic polymer, the behaviour of ternary catalytic systems based on violet TiCl3—Al(C2H5)Cl2-LEWIS base for ratios of Lewis bas/Al from 0 to ca. 1 was studied. Under the experimental conditions, all systems prepared with sufficiently weak bases are active in the polymerization, also for values of the ratio LEWIS base/Al somewhat 〉 1. The systems with strong bases are active only if the ratio LEWIS base/Al 〈 1. All the active systems show the same degree of stereospecificity as the binary systems prepared from violet TiCl3 and Al(C2H5)2Cl.The results confirm the interpretation that aluminum monoalkyldihalide is dismuted at least in part by the LEWIS base, with consequent formation of aluminum dialkyl monohalide at least partially non complexed; this compound, in the monomeric, non associated state should participate in the formation of the catalytic complexes. The hypotheses agree with the results of the polymerization of propylene and of butadiene of similar systems.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1964.020700115
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  • 5
    Electronic Resource
    Electronic Resource
    The nature of active components in catalytic systems prepared from TiCl3, monoalkylaluminum dihalides, and electron-donor substances, in the polymerization of propylene (1963)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A: General Papers 1 (1963), S. 403-409 
    Details
    ISSN: 0449-2951
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The reaction of two molecules of AlRCl2 with an electron donor molecule D, gives rise to the practically quantitative formation of AlR2Cl and AlCl3.D. This can explain the catalytic activity in the stereospecific polymerization of propylene to isotactic polymer of the systems prepared from violet TiCl3, AlRCl2, and an electron-donor substance. These systems have the same degree of stereospecificity as the systems consisting of AlR2Cl—TiCl3 (violet).
    Additional Material: 3 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1963.100010136
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