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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 3019-3024 
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The preparation of a high cis-1,4-polybutadiene, using a novel ternary catalyst system composed of triethylaluminum, a soluble nickel compound, and boron trifluoride diethyl etherate has been reported in the literature. The present paper reports the polymerization results obtained when the triethylaluminum was replaced with other alkylaluminums and the BF3 · Et2O was replaced with other BF3 complexes or HF · Et2O. When utilizing BF3 · Et2O, both the polymerization rate and the polymer DSV decreased significantly as the length of the alkyl group in the alkylaluminum increased from C1 to C6. However, the length and nature of the alkyl group had virtually no effect when utilizing BF3 · phenolate (BF3 · 2C6H5OH) and only a small effect with HF · Et2O; although the length of the alkyl group had no significant effect when using BF3 complexes of aromatic aldehydes, the branched alkyl groups gave greater polymerization rates than did the corresponding n-alkyls. In summary, the strongly acidic complexes, BF3 · phenolate and HF · etherate, promoted rapid polymerization when employed with any of the alkylaluminums. However, with other BF3 complexes, the alkylaluminum selected had an important influence upon either the conversion and/or the polymer DSV.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 2
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A quantitative procedure has been developed for characterizing the complete microstructure of polymers of 1,3-pentadiene, including the tacticity of any crystalline component. This can be accomplished by a combination of infrared spectroscopy, X-ray crystallinity, and 300-MHz NMR spectroscopy. A series of high structural purity polymers were synthesized with a series of previously unreported mixed microstructures. These samples were characterized by using the three techniques mentioned, including the previously unreported 300-MHz NMR data. With those results a 60-MHz NMR/IR method of spectroscopy was developed to determine the composition of poly(1,3-pentadiene)s in terms of percent cis-1,2-, cis-1,4-, trans-1,4-, and 3,4-pentadiene units.
    Additional Material: 15 Ill.
    Type of Medium: Electronic Resource
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