Pitch fiber

Data from the following technical data sheets PAN fibers Amoco Performance Products, Asahi Kasei, BASE Stmctural Materials, Courtaulds-Grafil, Hercules, Mitsubishi Rayon, Toho Beslon, Toray Pitch fibers Amoco Performance Products, Mitsubishi Kasei, Tonen Corp. 

Because of their unique blend of properties, composites reinforced with high performance carbon fibers find use in many structural applications. However, it is possible to produce carbon fibers with very different properties, depending on the precursor used and processing conditions employed. Commercially, continuous high performance carbon fibers currently are formed from two precursor fibers, polyacrylonitrile (PAN) and mesophase pitch. The PAN-based carbon fiber dominates the ultra-high strength, high temperature fiber market (and represents about 90% of the total carbon fiber production), while the mesophase pitch fibers can achieve stiffnesses and thermal conductivities unsurpassed by any other continuous fiber. This chapter compares the processes, structures, and properties of these two classes of fibers. 

A very unusual characteristic of mesophase pitch is the extreme dependency of its viscosity on temperature [19,34,35]. This factor has a profound influence on the melt-spinning process (described above), as a mesophase pitch fiber will achieve its final diameter within several millimeters of the face of the spinnerette, in sharp contrast to most polymeric fibers. 

Matsumoto, T. and Mochida, I., Oxygen distribution in oxidatively stabilized mesophase pitch fiber, Carbon, 1993,31(1), 143 147. 

Hamada, T., Nishida, T., Furuyama, M. and Tomioka, T., Transverse structure of pitch fiber from coal tar mesophase pitch. Carbon, 1988, 26(6), 837 841. 

The future remains bright for the use of carbon materials in batteries. In the past several years, several new carbon materials have appeared mesophase pitch fibers, expanded graphite and carbon nanotubes. New electrolyte additives for Li-Ion permit the use of low cost PC based electrolytes with natural graphite anodes. Carbon nanotubes are attractive new materials and it appears that they will be available in quantity in the near future. They have a high ratio of the base plane to edge plain found in HOPG. The ultracapacitor application to deposit an electronically conductive polymer on the surface of a carbon nanotube may be the wave of the future. 

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