Mesophase pitch carbon fiber

Figure 1. Scanning electron micrograph of fracture surface of a mesophase pitch carbon fiber etched with chromic acid to reveal the radial arrangement of constituent lamellar molecules.

Both isotropic and mesophase pitch carbon fibers are made from the same feedstock. 

Figure 7.13 Structural transition from random to radial transverse texture in a mesophase pitch carbon fiber after heat treatment up to 2800°C. Source Reprinted from Edie DD, Research into pitch based carbon fibers. In Genisio M ed.. Recent Research into Carbon-Carbon Composites, Southern Illinois University, 16-41, 1987.

Mochida I, Zeng SM, Korai Y, Hino T, Toshima H, Structure and properties of mesophase pitch carbon fiber with a skin core structure carbonized under strain, J Mater Sci, 27(7), 1960-1968, 1992. 

Cross Section. The cross-section structure of mesophase-pitch carbon fibers is one of the four types shown in Fig. 8.12 and is determined by the spinning method, the temperature of stabilization, and the partial pressure of oxygen.The formation of a skin-core structure or skin effect is often observed. This structure is similar to that of the PAN-based carbon fiber shown In Fig. 8.8 above. 

Fig. 8 High resolution Bjg spectra by XPS of two different types of boron-doped graphite and mesophase pitch carbon fibers. Reproduced from Ref. [6]...

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. 

Figure 17. Transmission electron micrographs of PAN-based and mesophase-pitch-based carbon fibers, as delivered and after heat treatment (42,43). HT and HM refer to high strength and high modulus PAN-based fibers P55 and P100 refer to mesophase-pitch-based fibers, with tensile moduli of 55 and 100 Mpsi, respectively.

Amoco has developed a family of ultra high modulus continuous graphite fibers and preforms with axial thermal conductivity to llOOW/mK. The extremely high thermal conductivity is a direct result of an extremely high degree of crystallinity during carbonization of the mesophase pitch precursor fiber. Table... 

Yoon, S.-H., Korai, Y., and Mochida, I. (1996). Axial nano-scale microstructures in graphitized fibers inherited from liquid crystal mesophase pitch. Carbon, 34, 941-56. 

Isotropic pitches are used to make a general purpose (GP) grade of pitch carbon fiber, which is not graphitic and has poorer properties than the high performance grade (HP), which requires a special treatment process to convert the pitch to a mesophase grade, i.e., an optically anisotropic and graphitic material. 

Lavin JG, Chemical reactions in the stabilization of mesophase pitch-based fibers. Carbon, 30, 351-357, 1992. 

Edie DD, Fain CC, Melt spun non-circular fibers from mesophase pitch. Carbon 86, Proceedings of the International Conference on Carbon, Baden-Baden, FRG, 629-631, 1986. 

Christ K, Huttinger KJ, Carbon-fiber-reinforced carbon composites fabricated with mesophase pitch, Carbon, 31(5), 731-750, 1993. 

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