THE HYDROCHLORINATION OF TRANS-1,4-POLYISOPRENE CRYSTALLIZED FROM SOLUTION (CARBON-13).
Item
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Title
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THE HYDROCHLORINATION OF TRANS-1,4-POLYISOPRENE CRYSTALLIZED FROM SOLUTION (CARBON-13).
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Identifier
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AAI8629750
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identifier
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8629750
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Creator
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TISCHLER, FRANCES.
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Contributor
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Arthur E. Woodward
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Date
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1986
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Language
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English
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Publisher
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City University of New York.
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Subject
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Chemistry, Polymer
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Abstract
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Solution grown lamellas and hedrites of trans-1,4-polyisoprene (TPI) in the (alpha) form, prepared by precipitation from amyl acetate, were reacted in suspension using an excess of HCl at -7 to -10(DEGREES)C. The product was followed with time. The resulting regular block copolymers were quantitatively analysed by 50.33 MHz carbon-13 NMR spectroscopy using assignments made with the aid of solution hydrochlorinated TPI. The average number of monomer units in the reacted () and unreacted () blocks were thus obtained. When acetone was used as the reacting medium remained constant after 1-2 days of hydrochlorination at an average value of 4.8 +/- 0.3; the average value of increases with the crystallization temperature, T(,c). The hydrochlorination fraction is approximately one-half the noncrystalline fraction calculated from density measurements. The block copolymers were dissolved in CDCl(,3), in 4-methyl-2-pentanone or in heptane and precipitated by solvent evaporation or by cooling. DSC and x-ray diffraction suggest that the product is noncrystalline. When hydrochlorination was carried out in amyl acetate suspension a 'peeling-off' effect occurred with HCl penetration into the crystalline core, particularly at T(,c)'s of 10 and 20(DEGREES)C. Wide angle x-ray diffraction studies show the presence of some completely hydrochlorinated material in the product. 100% reacted TPI is shown by x-ray diffraction and by DSC to be crystalline.
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Type
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dissertation
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Source
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PQT Legacy CUNY.xlsx
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degree
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Ph.D.
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Program
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Chemistry
