RAMAN-SPECTRUM OF MODIFIED PAN-BASED CARBON-FIBERS DURING GRAPHITIZATION

Graphite fibers were developed from polyacrylonitrile (PAN) fibers whi ch were modified with potassium permanganate. After the transitional t emperature, the formation of graphite structures commenced, the crysta ls increased in thickness, and the preferred orientation of the fiber crystals increased. The Raman specific absorption peak of noncrystalli ne carbon layers (1360 cm(-1)) weakened with the increase in the graph itization temperature, whereas the degree of graphitization rose. The results of this analysis indicate that manganese has the effect of cat alyzing graphitization, thus increasing the mechanical properties of t he graphite fibers. (C) 1996 John Wiley & Sons, Inc.