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  • 1
    Electronic Resource
    Electronic Resource
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 42 (1991), S. 851-861 
    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: Several boron-containing organosilicon polymers were synthesized from a sodium-coupling reaction of silicon and boron halides with and without alkyl halide in hydrocarbon solvents. The B-Si preceramic polymers were characterized using techniques such as IR, UV, and NMR spectrometry, gel permeation chromatography, elemental analysis, molecular weight measurement, and thermal analyses (TGA, DSC, DTA, and TMA). The chemical structures of the preceramic polymers were postulated based on the analytical results. Black ceramic materials were obtained from the precursor polymers upon thermal degradation at temperatures above 1000°C in an inert atmosphere. The precursor polymers had a ceramic yield of up to 70%. Thermogravimetric analysis of the ceramic material in air at a flow rate of 100 mL/min showed it was stable up to 1000°C with little weight gain or loss. Several methods were used to characterize the ceramic materials: XRD, solid NMR, high-temperature DTA, elemental analysis, and acid digestion. The analyses indicated that the ceramic materials comprised a mixture of silicon carbide (SiC), silicon borides (SiB4, SiB6), and amorphous Si-B-C ceramics, with small amounts of silica and free silicon.
    Additional Material: 5 Ill.
    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: The crosslinking or curing reaction of polystyrylpyridine (PSP) has been studied by means of thermal reactions of its model compounds. Compounds 2,6-distyrylpyridine, 4-stilbazole (4-styrylpyridine), and deuterated 4-stilbazole were pyrolyzed at 200-325°C both in air and under vacuum in a sealed tube. The major pyrolysis products were diarylethane and stilbene, and were characterized by gas chromatography-mass spectrometry. Major dimeric products were naphthalene or quinoline derivatives. Mechanisms for the pyrolysis are suggested, and a crosslinked structure for cured PSP is proposed based on the thermal reaction products of model compounds.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
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