Influence of Ozone Treatment on Oxidative Stabilization Behavior of Coal-tar-based Isotropic Pitch Fibers

Abstract: In this work, we performed ozone treatment of isotropic pitch fibers to optimize the duration and tempera-ture during the stabilization process. The treatment worked effectively for long-term and high-temperature stabiliza-tion. The isotropic pitch fibers were ozone-treated at different ozone concentrations of 10, 20, and 30 mg/l. The surfaceproperties of the isotropic pitch fibers were analyzed by Fourier transform infrared spectroscopy, X-ray photoelectronspectroscopy, and scanning electron microscopy, while their structural characteristics were examined using X-ray dif-fraction. The experimental results indicated that the surface oxygen functional groups (COOH, OH, and CO) and oxy-gen concentration of the pitch fibers increased after the ozone treatment. During the oxidative stabilization process, thecross-linking reactions of the oxygen functional groups formed the thermosetting pitch, as confirmed by the replace-ment of hydrogen with oxygen. Additionally, it was observed that the ozone treatment could improve the optimizedoxidative stabilization procedure in carbon fiber manufacturing. Therefore, the ozone treatment played an importantrole in optimizing the oxidative stabilization procedure of the pitch fibers.Keywords: isotropic pitch fibers, ozone treatment, oxidative stabilization, X-ray diffraction

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