GROWTH AND PROPERTIES OF (TRANS 1,4-POLYISOPRENE) CRYSTALS.
Item
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Title
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GROWTH AND PROPERTIES OF (TRANS 1,4-POLYISOPRENE) CRYSTALS.
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Identifier
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AAI8401887
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identifier
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8401887
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Creator
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ANANDAKUMARAN, KANAPATHIPPILLAI.
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Contributor
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Arthur E. Woodward
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Date
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1983
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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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Crystals of trans 1,4-polyisoprene in the (alpha) form were prepared from dilute amyl acetate solution employing the self seeding technique and crystallizing at T(,C)'s of 10 to 34(DEGREES)C using fractions of Balata and Gutta Percha with M(,n) from 2 x 10('4) to 4 x 10('5) and M(,w)/M(,n) of 1.2 - 1.5. With a change of T(,C) from 10 to 30(DEGREES)C the lamellar thickness showed an increase from 78 to 125(ANGSTROM), the DSC endotherm increased from 58 to 68(DEGREES)C, the density changed from 0.96 to 0.98g cm('-3) and the morphology changed from ellipsoidal to hexagonal. A similar effect in morphology and density was found on decreasing the M(,n) from 10('5) to 10('4).;The total noncrystalline fraction l-W(,C) was determined from the density values and the surface fraction, F(,S), for selected preparations by an epoxidation reaction. The epoxidation reaction was carried out on the crystals in amyl acetate suspension at 0(DEGREES)C as a function of time using m-chloroperbenzoic acid (MCPBA) until the reaction levelled off. It was found that crystal damage during the epoxidation reaction increases with increasing M(,n), (MCPBA), with increasing reaction time and with decreasing T(,C). The number of monomer units per fold, calculated from the epoxidation results was smallest for M(,n) = 2.4 x 10('4) (6) and showed an increase with increasing T(,C) at constant M(,n) (8 to 10).
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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
