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  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    The @journal of organic chemistry 41 (1976), S. 1667-1668 
    ISSN: 1520-6904
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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  • 2
    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: In order to improve the separation characteristics of membranes for pervaporation, the introduction of fluoroalkyl groups into poly(1-trimethylsilyl-1-propyne) (PTMSP) was achieved by two methods. First, 3,3,3-trifluoropropyldimethylsilylated PTMSP was prepared via metalation of PTMSP followed by treating with 3,3,3-trifluoropropyldimethylchlorosilane. About 6 mol % of 3,3,3-trifluoropropyldimethylsilyl group was introduced by the polymer reaction. Second, the copolymerizations of 1-trimethylsilyl-1-propyne (TMSP) with 1- (3,3,3-trifluoropropyldimethylsilyl)-1-propyne (FPDSP) or 1- (1H,1H,2H,2H-tridecafluorooctyldimethylsilyl)-1-propyne (FODSP) were carried out to afford TMSP/FPDSP or TMSP/FODSP random copolymers. The ratio of TMSP monomer unit and the comonomer unit, x/y, was in the range of 99/1-85/15. All the chemically modified PTMSP membranes showed ethanol permselectivity for pervaporation of aqueous ethanol solution. In particular, the introduction of less than about 5 mol % of fluoroalkylsilylated units into PTMSP effectively enhanced the selectivity. However, excess introduction of FODSP comonomer unit caused a decrease of the selectivity, with the value being smaller than that of PTMSP membrane. Furthermore, tetrahydrofuran, acetone, acetonitrile, dioxane, and isopropanol were efficiently separated from their dilute aqueous solutions using a TMSP/FPDSP copolymer membrane.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 32 (1986), S. 4137-4143 
    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: Anion exchange membranes with excellent durability were prepared by chemical modification of Nafion. The modification was achieved by transformation of the sulfonic acid group into quaternary ammonium group. Namely, Nafion membrane was first converted into an amide-type membrane. Reduction of the carbonxyl group to methylene followed by quaternarization with alkyl iodide resulted in the formation of an anion exchange membrane. The electric resistance of the resulting membranes depends on the equivalent weight of the starting membranes (4.4-6.0 Ω cm2 in 0.5N NaCl). The characteristics of the membranes are the excellent stability toward chemical substances such as organic solvents, oxidizing agents, acids, etc. For example, the membranes are stable in aqueous saturated chlorine solution at 60°C for 1000 hr.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
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