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  • 1
    Electronic Resource
    Electronic Resource
    Iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal. II. Properties of copolymer obtained by beaker-scale copolymerization (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 723-733 
    Details
    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 elucidate the copolymerization mechanism, the properties of the copolymer obtained by the iodine-initiated copolymerization of the tetraoxane-1,3-dioxolane-methylal system have been studied using gas chromatography, microscopy, scanning electron microscopy, differential scanning calorimetry, and gel permeation chromatography. From the behavior of the thermal stability and gas chromatography of the reaction mixture, it was found that reactivity of 1,3-dioxolane with active center is larger than that of tetraoxane, i.e., more than 90% 1,3-dioxolane is consumed at an early stage of the polymerization. The results obtained by microscopy, DSC, and GPC of the copolymer suggested that the copolymerization proceeds from the surface to the center of the tetraoxane crystal as if it were a core model. It was also suggested that the heterogeniety in copolymer properties can be explained not only by heterogeneous dispersion of 1,3-dioxolane in tetraoxane crystal, but also by the difference of reactivity of 1,3-dioxolane with the active center.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1977.070210313
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  • 2
    Electronic Resource
    Electronic Resource
    Iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal. IV. Fractional dissolution of copolymer (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 749-759 
    Details
    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: A fractional dissolution on the oxymethylene copolymer obtained by the iodine-initiated, solid-state copolymerization of the tetraoxane-1,3-dioxolane-methylal system has been carried out using a mixed solvent which consists of tetrachloroethane, phenol, and cyclohexanol. On the fractional dissolution, the oxymethylene copolymer was divided mainly into two parts: one was the copolymer containing a larger amount of ethylene oxide unit in its main chain and having lower molecular weight; the other was copolymer containing a smaller amount of ethylene oxide unit and having a higher molecular weight. It was reasonably concluded that in this copolymerization system, the reaction proceeds from the surface to the center of the tetraoxane crystal to give a divided copolymer due to the heterogeneous properties such as copolymer composition and molecular weight.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1977.070210315
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  • 3
    Electronic Resource
    Electronic Resource
    Iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal. V. Studies on molecular weight distribution of copolymer (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 3383-3394 
    Details
    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: The iodine-initiated, solid-state copolymerization of the tetraoxane-1,3-dioxolane-methylal system has been studied by measuring the molecular weight distribution of the copolymer. The molecular weight distribution of the copolymer is found to be strongly dependent on the addition method of the 1,3-dioxolane-methylal solution to tetraoxane. The copolymer obtained by the one-addition copolymerization has a molecular weight distribution curve that shows a very broad distribution, with a discernible shoulder; and the copolymer obtained by the continuous-addition copolymerization has a very sharp curve. Particle size of the copolymer also influences the molecular weight distribution. For the one-addition copolymerization, the larger the particle size of the copolymer, the broader the molecular weight distribution. For the continuous-addition copolymerization, however, the molecular weight distribution is nearly constant regardless of particle size. The dependence of the molecular weight distribution on the polymerization time and the concentrations of iodine, 1,3-dioxolane, and methylal is discussed in detail. These results suggest that this copolymerization system is characterized by a reaction that proceeds from the surface to the center of the tetraoxane crystals.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070231122
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  • 4
    Electronic Resource
    Electronic Resource
    Iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal. VIII. Mechanical properties of copolymer (1979)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 23 (1979), S. 3421-3426 
    Details
    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: Copolymers obtained by the solid-state copolymerization of tetraoxane with 1,3-dioxolane were pelletized using a vent-type extruder and the mechanical properties were measured. The mechanical properties were found to be largely influenced by the distributions of molecular weight and ethylene oxide, which were controlled by the addition method of the 1,3-dioxolane-methylal solution into polymeric system. The mechanical properties of the copolymers were also found to be intermediate between those of Duracon M90 and Delrin 500.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1979.070231125
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  • 5
    Electronic Resource
    Electronic Resource
    Iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal. I. Fundamental study on beaker-scale copolymerization (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 711-722 
    Details
    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: The iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal has been studied on a beaker scale. It was found that tetraoxane can be easily copolymerized with 1,3-dioxolane by a small amount of iodine as initiator and gives oxymethylene copolymer with excellent thermal stability in a high yield. The copolymerization was largely influenced by the concentrations of iodine, 1,3-dioxolane, and methylal, i.e., the polymerization rate increased with increase not only in iodine but also in 1,3-dioxolane, and the thermal stability and the molecular weight of the copolymer were mainly affected by 1,3-dioxolane and methylal concentration, respectively.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1977.070210312
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  • 6
    Electronic Resource
    Electronic Resource
    Gel permeation chromatography of polyoxymethylene (1974)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 18 (1974), S. 1927-1942 
    Details
    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: Gel permeation chromatography of polyoxymethylene has been studied using N,N-dimethylformamide as the solvent. Polyoxymethylene samples used here are a copolymer of tetraoxane with 1,3-dioxolane and a commercial polyoxymethylene whose molecular weight distributions are moderately broad. Their intrinsic viscosities [η] range from 1.4 to 2.8 dl/g. Factors affecting chromatograms are discussed, and the operating conditions were determined by using the analytical scale GPC. On the basis of these operating conditions, the molecular weight fractionation of polyoxymethylene was carried out by using the preparative scale GPC. It was found that polyoxymethylene can be effectively fractionated to give seven to ten fractions each of them containing the fractionated polymer ranging in weight from 0.2 to 8 mg when 40 mg polymer sample was used for a run of the measurement. The fractionated polymers were also found to have a narrow molecular weight distribution within a single peak, and their Mw/Mn values decrease with increasing molecular weight.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1974.070180703
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  • 7
    Electronic Resource
    Electronic Resource
    Iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal. III. Study on larger-scale copolymerization (1977)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 21 (1977), S. 735-748 
    Details
    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: The iodine-initiated, solid-state copolymerization of tetraoxane with 1,3-dioxolane in the presence of methylal has been studied using 15 l kneader-type reactor. Effects of the addition method of the 1,3-dioxolane-methylal solution on the copolymerization has been mainly discussed. The copolymerization rate, intrinsic viscosity, and thermal stability of the copolymer were found to be largely dependent on the addition method of the 1,3-dioxolane-methylal solution, i.e., if the solution is added all at once, properties of the copolymer are different at the early stage then at the later stage of the copolymerization, while on successive addition of the solution, the copolymer properties become almost constant irrespective of the polymerization time. Therefore, it was suggested that 1,3-dioxolane and methylal can easily diffuse through the copolymer layer formed on the surface of the tetraoxane particle and reacts with an active center as copolymerization proceeds.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1977.070210314
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