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  • 1
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Macromolecules 28 (1995), S. 7331-7334 
    ISSN: 1520-5835
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 1007-1012 
    ISSN: 0887-624X
    Keywords: seven-membered cyclic sulfite ; oxetane ; cationic copolymerization ; block copolymerization ; one-shot feeding ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cationic copolymerization of seven-membered cyclic sulfite, 1,3,2-dioxathiepane-2-oxide (1) and oxetane (2) in one-shot feeding was carried out to obtain the corresponding copolymer. When a mixture of equimolar amount of 1 and 2 reacted at 0°C in the presence of methyl trifluoromethanesulfonate (T fOMe) as a cationic initiator, T fOMe and 2 were completely consumed without the consumption of 1. After rising the polymerization temperature up to 25°C, 1 started to be consumed to obtain the corresponding copolymer of 1 and 2. The obtained copolymer showed a unimodal GPC curve, and it afforded a polyether showing a unimodal GPC after alkaline hydrolysis. These results strongly suggested the occurrence of the block copolymerization in one-shot feeding. From the molecular orbital examination, the formation of block copolymerization in one-shot feeding was discussed to be caused by the much larger polymerizability of 2 than that of 1. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 1007-1012, 1997
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
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  • 4
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 3235-3240 
    ISSN: 0887-624X
    Keywords: seven-membered cyclic sulfite ; six-membered cyclic sulfile ; cationic equilibrium polymerization ; depolymerization ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cationic polymerization of a seven-membered cyclic sulfite (7CS) was carried out with methyl trifluoromethanesulfonate as a catalyst in chlorobenzene. The final conversions of 7CS were 22, 41, 52, and 60% in the polymerizations at 25°C with the initial monomer concentrations of 3, 4, 5, and 6M, respectively. The calculated monomer concentration at equilibrium was evaluated as 2.4M in any case. The conversion of 7CS decreased as the polymerization temperature rose. These results support the fact that this polymerization is an equilibrium one. ΔH0 and ΔS0 in the polymerization were evaliuated as -0.765 kcal/mol and -4.18 cal/mol by Dainton's equation, respectively. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3235-3240, 1997
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 35 (1997), S. 3673-3682 
    ISSN: 0887-624X
    Keywords: seven-membered cyclic sulfite ; cationic polymerization ; desulfoxylation ; volume expansion ; Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cationic ring-opening polymerization behavior of a seven-membered cyclic sulfite (1) was examined. 1 was prepared by the reaction of 1,4-butanediol with SOCl2 in 58% yield. The cationic polymerization of 1 was carried out at 0, 25, 60, or 100°C with trifluoromethanesulfonic acid (TfOH), methyl trifluoromethanesulfonate (TfOMe), BF3 · OEt2, SnCl4, methyl p-toluenesulfonate (TsOMe), or MeI as an initiator in bulk under a nitrogen atmosphere to afford the polymer with M̄n 1000-10,400. The order of activities of the initiators for 1 was as follows, TfOH ≅ TfOMe 〉 SnCl4 〉 BF3 · OEt2 〉 TsOMe ≅ MeI. The polymerization of 1 with TfOMe afforded a poly(sulfite) below 25°C, but afforded a polymer containing an ether unit at 60°C, which was formed by a desulfoxylation. The higher the activity of the initiator was, the more easily the desulfoxylation occurred. We expected volume expansion on polymerization because cyclic sulfites have large dipole moment values, but it turned out that 1 showed 4.34% shrinkage on polymerization. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35: 3673-3682, 1997
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Macromolecular Chemistry and Physics 199 (1998), S. 1785-1789 
    ISSN: 1022-1352
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The cationic polymerization of five- and eight-membered cyclic sulfites (5CS and 8CS) was examined. The monomer 5CS polymerized in the presence of cationic initiators such as TfOMe, BF3 · OEt2, and TsOMe in bulk to afford a polyether, accompanied by quantitative desulfoxylation. On the other hand, 8CS polymerized without desulfoxylation. Ring strains of 5CS and 8CS were evaluated by molecular orbital (MO) calculations, which confirmed the larger ring-strain of 8CS compared with 5CS.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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