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  • 1965-1969  (9)
  • 1
    Electronic Resource
    Electronic Resource
    Polymerization of tetraoxane at low concentration catalyzed by BF3·O(C2H5)2 (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2997-3007 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the solution polymerization of tetraoxane catalyzed by BF3·O(C2H5)2, trioxane and methanol-insoluble polymer were produced. However, the amounts of these products depend on the nature of solvent used. A critical concentration of tetraoxane is observed for the formation of methanol-insoluble polymer; at less than this critical concentration of tetraoxane no methanol-insoluble polymer is obtained, but trioxane is preferentially produced. This critical concentration of tetraoxane is higher in a more polar solvent, so the amount of methanol-insoluble polymer produced decreases and the amount of trioxane produced increases with increasing the polarity of solvent used. These results may be explained in terms of a stabilization of the active center leading to formation of trioxane by a solvation with solvent.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.150051203
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  • 2
    Electronic Resource
    Electronic Resource
    Changes in concentration of tetraoxane produced during the solution polymerization of trioxane catalyzed by BF3·O(C2H5)2 (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2977-2988 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The behavior of tetraoxane produced during the polymerization of trioxane was investigated kinetically. In the polymerization of trioxane, a short induction period for the formation of methanol-insoluble polymer was observed and during the induction period a certain amount of tetraoxane, depending on the polymerization conditions, was produced. This amount was independent of the initial concentration of catalyst but increased with an increase in the polymerization temperature and in the initial concentration of trioxane. So this amount was found to be determined by the equilibrium between the formation and consumption of tetraoxane. On the other hand, in the early stage of polymerization of trioxane, the formation of an appreciable amount of soluble polymer was estimated. Consequently the formation of tetraoxane was explained in terms of the “back-biting” reaction of the soluble growing chain with depolymerization.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.150051201
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  • 3
    Electronic Resource
    Electronic Resource
    Rates of polymer formation and monomer consumption in the solution polymerization of trioxane catalyzed by BF3 · O(C2H5)2 (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 95-106 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the solution polymerization of trioxane catalyzed by BF3 · O(C2H5)2 at 30°C. the amount of the methanol-insoluble polyoxymethylene is less than the amount of monomer consumed. This difference was much larger than the amount of formaldehyde determined in the polymerized system and could not also be explained in terms of the amount of the methanol-soluble oligomer. Tetraoxane was detected in large quantities by gas chromatography in the polymerized solution of trioxane. Therefore, the difference between the amounts of the methanol-insoluble polymer and the monomer consumed was ascribed partly to the formation of tetraoxane. In spite of the fact that tetraoxane was polymerized more easily than trioxane by BF3 · O(C2H5)2, an almost constant amount of tetraoxane was produced, independent of the kind of solvent and the polymer yield. This suggests the existence of an equilibrium concentration of tetraoxane. On the other hand, the formation of trioxane was observed in the solution polymerization of tetraoxane by BF3 · O(C2H5)2. This suggests that the formation of tetraoxane during the trioxane polymerization is due to a back-biting reaction in which the growing chain end of trioxane attacks the oxygen atom in its own chain with depolymerization of tetraoxane.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.150050108
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  • 4
    Electronic Resource
    Electronic Resource
    Copolymerization of tetraoxane with styrene catalyzed by BF3·O(C2H5)2 (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1937-1949 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The copolymerization of tetraoxane with styrene catalyzed by BF3·O(C2H5)2 was studied at 30°C. to determine whether a cyclic monomer can copolymerize with a vinyl monomer. The formation of the copolymer was confirmed by elementary analysis of both benzene-soluble and benzene-insoluble fractions of the polymer obtained. It was found by gas chromatography that a fairly large amount of 4-phenyl-1,3-dioxane and a small amount of trioxane were formed in the present system, in addition to polymers. Roughly a third of the total amount of the monomers reacted was consumed in the formation of methanol-insoluble polymer, a third for 4-phenyl-1,3-dioxane, and another third for trioxane and unknown products which could not be indentified. The formation of these cyclic compounds during the copolymerization may be explained in terms of a back-biting (or intramolecular transacetalization) reaction. The cationic reactivity of tetraoxane was found to be similar to that of styrene on the basis of both the consumption rate of each monomer in the copolymerizing system and the composition of the methanol-insoluble polymer obtained.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.150050811
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  • 5
    Electronic Resource
    Electronic Resource
    Solution polymerization of trioxane catalyzed by stannic chloride (1968)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 6 (1968), S. 3031-3040 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polymerization of trioxane catalyzed by stannic chloride (SnCl4) in ethylene dichloride was studied and compared with the results obtained with boron trifluoride etherate, BF3·O(C2H5)2, as catalyst. Under the same conditions, the polymerization rate was larger with SnCl4 than with BF3·O(C2H5)2, while at a fixed polymer yield the molecular weight of the polymer obtained by SnCl4 was lower than with the BF3·O(C2H5)2 catalyzed reaction. The overall activation energy of trioxane polymerization with SnCl4 was 11.0 ± 0.8 kcal/mole. The kinetic orders of catalyst and monomer were determined to be close to 2 and 4, respectively. A certain amount of tetraoxane was also produced in an early stage of the polymerization with SnCl4 similar to BF3·O(C2H5)2-catalyzed reaction. However, the maximum amount of tetraoxane produced at 30°C was larger with SnCl4 than with BF3·O(C2H5)2. In addition, a ten-membered ring compound (pentoxane) was isolated in the solution polymerization of trioxane catalyzed by both SnCl4 and BF3·O(C2H5)2. The confirmation of pentoxane formation is strong evidence for the back-biting reaction mechanism.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1968.150061107
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  • 6
    Electronic Resource
    Electronic Resource
    1,3,5-Trioxacycloheptane formation in the cationic polymerization of 1,3-dioxolane (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Letters 5 (1967), S. 583-587 
    Details
    ISSN: 0449-2986
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.110050708
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  • 7
    Electronic Resource
    Electronic Resource
    Copolymerization of trioxane with styrene catalyzed by BF3·O(C2H5)2 (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 1927-1936 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It was determined whether trioxane, a cyclic formal, can copolymerize with styrene, a vinyl monomer, in the presence of BF3·O(C2H5)2 catalyst at 30°C. The methanol-in-soluble fraction after extraction with benzene was found to contain the copolymer of styrene and trioxane, thus demonstrating that trioxane can copolymerize with styrene In this case the amount of the methanol-insoluble polymer was less than that of the total monomer consumed, as determined by gas chromatography. This was found to be caused partly by the formation of the cyclic oligomer, 4-phenyl-1,3-dioxane. The relative reactivity of styrene was qualitatively found to be larger than that of trioxane, not only from the rate of monomer consumption but also from the composition of the methanol-insoluble polymer obtained. In a nonpolar solvent the reactivity of trioxane increased, and the difference in reactivity between the two monomers decreased. Indeed, an apparent monomer reactivity ratio might be obtained from the relationship between the monomer composition and the monomer consumption rate or the composition of the methanol-insoluble polymer, but it did not have a quantitative meaning because of the complexity of the copolymerization reaction.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.150050810
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  • 8
    Electronic Resource
    Electronic Resource
    Effect of solvent on the amount of tetraoxane produced in the solution polymerization of trioxane catalyzed by BF3·O(C2H5)2 (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part A-1: Polymer Chemistry 5 (1967), S. 2989-2996 
    Details
    ISSN: 0449-296X
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The amounts of tetraoxane produced in the polymerization of trioxane catalyzed by BF3·O(C2H5)2 were measured in various solvents. The maximum amount of tetraoxane produced depends on the nature of solvent used. This amount was independent of the initial concentration of the catalyst in ethylene dichloride and in nitrobenzene. On the other hand, in benzene, the amount of tetraoxane produced decreased slightly with increasing initial catalyst concentration. This result was explained by the reaction of tetraoxane produced with the residual catalyst as well as with the active center. The maximum amount of tetraoxane produced decreased, other conditions being similar, in the order, nitrobenzene 〉 ethylene dichloride 〉 benzene solvent. This order may be explained in terms of a longer lifetime of the active center in the more polar solvent, leading to the formation of tetraoxane.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.150051202
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  • 9
    Electronic Resource
    Electronic Resource
    Trioxane formation in the solid-state polymerization of tetraoxane (1967)
    New York : Wiley-Blackwell
    Journal of Polymer Science Part B: Polymer Letters 5 (1967), S. 65-67 
    Details
    ISSN: 0449-2986
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1967.110050111
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