Preparation and Characterization of Highly Oriented Ribbon Shape Pitch-based Carbon Fibers

Using a naphthalene derived mesophase pitch as starting material,high oriented ribbon-shaped carbon fi-bers with smooth and flat surface were prepared by melt-spinning,oxidation stabilization as well as further carboniza-tion and graphitization processes.The composition,morphologies and microstructure of the ribbon-shaped carbon fi-bers treated at various conditions were characterized by elemental analyses,IR spectroscopy,XRD,Raman spectro-scope,scanning electron microscope and polarized-light microscope.The results show that the carboxyl,carbonyl and ether functional groups formed during the oxidizing stabilization process are removed by subsequent carbonization treatment.The width and thickness of the ribbon-shaped fibers at the transverse section decrease from 1.6mm and 18μm of pitch fiber to 1.2mm and 9μm of graphitized carbon fibers,respectively.The relative intensity of the diffrac-tion peak at about 2? = 26? corresponding to(002) crystal plane of hexagonal graphite increases with the heat-treatment temperature increasing.This indicates that the crystal size of graphite in this carbon fibers also in-creases in this process.In comparison with the carbonized fibers,the carbon fibers after graphitization treatment dis-play more perfect crystal orientation along the main surface of ribbon-shaped carbon fibers.