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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 29 (1984), S. 933-939 
    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: Spinning speed is one of the most important process parameters for change in properties of yarn and efficiency of polyester production. In this paper the effect of spinning speed (3000-6200 ypm) on dynamic mechanical properties is presented, and shows a good qualitative picture on the influence of structure change on the dynamic modulus and the height and position of glass transition peak on POY (partially oriented polyester) and PTY (draw-textured polyester) yarns. The dynamic moduli of POY yarns in a temperature range of 25-160°C are increased with increasing spinning speed. Large glass transition peaks (α peak) are observed for POY yarn spun at 3000 and 2800 ypm at about 98°C. This indicates that the yarns are low oriented with low crystallinity (5-6%). But the Tg of POY spun at 5600 or 6200 ypm is about 125°C and shows about 35% crystallinity with high amorphous orientation. An approximately linear relation was found between the height of the loss peak (tan δ) and the degree of amorphous orientation (fa) by using these analyses.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 18 (1980), S. 2723-2729 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A mild, efficient method of nitrating olefins was described recently by Corey and Estreicher. Application of their procedure to diene polymers failed because of the insolubility of the hydrophobic polymer in the aqueous nitromercuration regent. Use of water-immiscible organic cosolvents gave slow nitromercuration with substantial formation of nitrite esters. To overcome these problems a nonaqueous phase transfer-assisted method of rapid selective nitromercuration of diene polymers was developed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Chemistry Edition 20 (1982), S. 1505-1516 
    ISSN: 0360-6376
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Iodine azide adds to cyclohexene in acetonitrile or 4:1 methylene chloride/acetonitrile to give trans-1-azido-2-iodocyclohexane. In methylene chloride this reaction gives a mixture of the cis-and trans-iodoazides owing to competing radical addition. Iodine azide adds to 1-hexene in acetonitrile by an ionic mechanism to give a 3:1 mixture of the 2-azido-1-azido- and 1-azido-2-iodohexanes. Dehydroiodination of the model iodoazides proceeds smoothly with potassium t-butoxide in diethyl ether or THF in the presence of 5 mol % 18-crown-6 at room temperature, giving in the previous example a mixture of 2-azido- and trans-1-azidohexenes. Polybutadiene, carboxyterminated poly(acrylonitrile-co-butadiene), and hydroxy-terminated polybutadiene gave iodoazide derivatives with up to 96% of the theoretical maximum nitrogen content and strong azide IR absorption. High azidoiodination gave polymer with N3/I ratios slightly higher than unity while low percent azidoiodination led to polymer with N3/I ratios of as low as 2:3. All of the nitrogen introduced was in the form of azide function. Dehydroiodination gave polymers with vinyl azide functionality and caused loss of some of the azide groups. All the azidoiodinated polymers decomposed between 120 and 160°C. The dehydroiodinated materials were less stable, decomposing between 100 and 150°C. The temperature of initial decomposition decreased as azide content increased. Polymers with 〉55-60% of the theoretical maximum azide content were shock sensitive.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
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