ELECTRONIC AND STRUCTURAL CHARACTERISTICS OF CARBON-FIBERS FROM MESOPHASE PITCH

The electronic properties (resistivity, magnetoresistance, and electron spin resonance) of mesophase pitch-based carbon fibers have been studied in relation to the fiber structure and processing conditions. Reproducible correlations between the electronic properties and the structure demonstrate that the electronic properties are a sensitive indicator of the degree of graphite order in the fibers. Fibers having radial transverse structure are more easily graphitized than fibers with random transverse structure. The effect of differences in the thermosetting procedure is relatively unimportant. The ultimate degree of graphitization attainable by these fibers is comparable to that of similarly heat-treated pyrolytic carbons, whereas PAN-based carbon fibers are ultimately capable only of properties comparable to pitch-based fibers treated in the 1700-2300°C range. © 1979.