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  • 1
    Electronic Resource
    Electronic Resource
    Preparation of high-performance carbon fibres from PAN fibres modified with cobaltous chloride (1992)
    Springer
    Journal of materials science 27 (1992), S. 2429-2436 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Preparations of high-performance carbon fibres have been tested and the results are reported in this article. Polyacrylonitrile (PAN) fibres modified with cobaltous chloride have increased the crystal size, the crystallinity and the orientation, and also improved the tensile strength by about 15–40% and the modulus by about 10–20% of the resulting carbon fibres, which were carbonized at 1300 °C. The oxygen content, theAI value and the density for the modified PAN fibres are smaller than those for unmodified PAN fibres. Because the formation of the ladder polymer in the modified PAN fibres is slow and gradual during the stabilization process, the resulting carbon fibres have a better modulus than carbon fibres developed from unmodified PAN fibres. The activation energy of cyclization,E a, is increased to 180.0 from 156.6 kJ mol−1 after the modification process. The modified PAN fibres do not reduce the time required for stabilization. The carbon fibres developed from the modified PAN fibres have a greater stacking size,L c, than those developed from unmodified PAN fibres. A higher stacking size, and therefore a higher number of crystalline carbon basal planes, is one of the reasons for the improved modulus of the carbon fibres.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01105054
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  • 2
    Electronic Resource
    Electronic Resource
    Study of the pyrolysis of phenolic resin reinforced with two-dimensional plain woven carbon fabric-I (1991)
    Springer
    Journal of materials science 10 (1991), S. 301-303 
    Details
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00735665
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  • 3
    Electronic Resource
    Electronic Resource
    The study of polyacrylonitrile-based activated carbon fibres for water purification: Part I (1992)
    Springer
    Journal of materials science 11 (1992), S. 6-8 
    Details
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00720764
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  • 4
    Electronic Resource
    Electronic Resource
    The effect of precarbonization on mechanical properties of final polyacrylonitrile-based carbon fibres (1993)
    Springer
    Journal of materials science 12 (1993), S. 343-345 
    Details
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01910099
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  • 5
    Electronic Resource
    Electronic Resource
    Preparation of graphite fibres from a modified PAN precursor (1992)
    Springer
    Journal of materials science 27 (1992), S. 6071-6078 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Graphite fibres were developed from polyacrylonitrile (PAN) fibres modified with potassium permanganate. To our knowledge, this is the first time that the effect of modification on the physical properties, microstructure, elemental composition, electrical resistivity, and mechanical properties of fibres has been examined during the graphitization process. The graphite fibres developed from modified PAN fibres had a higher density, a greater stacking size,L c, and a higher preferred orientation than those developed from unmodified PAN fibres. The graphite fibres also showed an improvement of 20%–40% in electrical resistivity and modulus.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01133752
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  • 6
    Electronic Resource
    Electronic Resource
    Characterization of PAN precursor modified with potassium permanganate (1988)
    Springer
    Journal of materials science 7 (1988), S. 628-630 
    Details
    ISSN: 1573-4811
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01730316
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  • 7
    Electronic Resource
    Electronic Resource
    Thermal stabilization of polyacrylonitrile fibers (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 35 (1988), S. 631-640 
    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: Polyacrylonitrile (PAN) fibers pretreated with potassium permanganate have reduced the activation energy of cyclization and the oxidation time, and also improved the properties of the resultant carbon fibers. The activation energy of cyclization is reduced to 24 ± 1 kcal/mol from 30 ± 3 kcal/mol and the tensile strength of the carbon fibers increases by about 20-40%. The method of measuring the “aromatization index” (AI) value is modified and is recommended in checking the oxidation process. All fully stabilized PAN fibers have almost the same AI value. However, the oxidation time is decreases by 30 min when oxidation temperature is raised by 10°C.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1988.070350306
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  • 8
    Electronic Resource
    Electronic Resource
    The microstructure of stabilized fibers (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 35 (1988), S. 863-874 
    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 morphology and microstructure of a stabilized fiber, nonburning fiber, has been investigated under optical and electron microscopes, and a model for the structure of the stabilized fiber is presented. Skin-core morphology was found in the cross section of the stabilized fiber. The proposed model is consistent with the lamellar-plate-like structure, measuring about 400-700 Å in thickness, 500-4000 Å in breadth and 0.1-0.5 μ m in length along the fiber axis, which is composed of microfibrils. The structure has some circumferential distribution in the outer zone, while the inner zone has a radical distribution. Evidence for the lamellar-plate structure, including two chemical structures and having two different crystalline phases, which are the original AN units and the ladder polymer, were obtained from electron microscopy, wide-angle X-ray, and electron diffraction analyses.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1988.070350402
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  • 9
    Electronic Resource
    Electronic Resource
    Structural changes and molecular motion of polyacrylonitrile fibers during pyrolysis (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 37 (1989), S. 553-566 
    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 stabilization process of polyacrylonitrile (PAN) fiber is necessary to develop high-performance carbon fiber. This work is concerned with studies of the activation energy of PAN fibers during the stabilization process. A wide-angle X-ray diffractometer combined with a fiber specimen holder for heating was used to measure the activation energy of crystal transition Ec. Ec is almost the same as the activation energy of the cyclization reaction E which is measured by a differential thermal analysis (DTA). The variation of crystal size in PAN fiber and a model of the ladder polymer in stabilized fiber transformed from acrylontrile (AN) units of PAN fiber are discussed also. The crystal size of PAN fiber increases when the thermal treatment temperature is raised. When exposed to temperatures above the crystal degradation temperature Td, the molecular rods of PAN fiber are destroyed completely, and ladder polymer is formed in the ordered phase of the original PAN fiber. The transformation of ladder polymer is initiated in the disordered phase, and then at the boundaries of the ordered phase.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1989.070370220
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  • 10
    Electronic Resource
    Electronic Resource
    The effect of modification on structure and dynamic mechanical behavior during the processing of acrylic fiber to stabilized fiber (1989)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 37 (1989), S. 541-552 
    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: Polyacrylonitrile (PAN) fibers pretreated with potassium permanganate have reduced the time required for stabilization, and also improved mechanical properties of the resultant carbon fibers. In this study, the effect of modification on the stabilization process and the dynamic mechanical properties of PAN fibers have been examined. The beta peak appeared at about 125°C on the loss tangent curves caused by molecular motion in the PAN fiber. Appearing at about 254°C, the alpha peak is attributed to chemical reactions and molecular motion in the formation of the crystalline phase of stabilized fibers. The alpha peak of the modified PAN fiber had lower absorption and had a smaller peak in the temperature range of 212-239°C. This indicated that potassium permanganate acts as a catalyst to lower the reaction temperature by about 20°C of the initial cyclization reaction. The dynamic storage modulus analysis indicated that modified PAN fibers have a lower initial transition temperature and that formation of the ladder polymer is gradual and steady.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1989.070370219
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