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Pre-oxidized polyacrylonitrile (PAN) fiber into a critical phase high-performance carbon fibers, accompanied by a high exothermic and complex chemical and physical transformation process, easy to produce pre-oxidation caused uneven skin-core structure, which greatly affect the carbon fiber performance. The traditional pre-oxidation process is generally taken to suppress the slow heating of the concentration of the release of heat, a lot of time and energy consumption, high cost of such carbon fibers, greatly suppressed in the wide range of applications in areas such civilian. Therefore, without prejudice to the premise of fiber properties, shortening the pre-oxidation time, reduce costs, carbon fiber has become the industrial production problems to be solved. In this paper, the above problem, the use of three different strands modification means that the radiation modification, chemical modification, irradiation chemical modification method of combining the right PANF were processed, a detailed study of raw silk Modification on pre-oxidized polyacrylonitrile process and pre-oxidized fiber performance. First, the use of novel radiation sources for PANF was modified. Comparison, the radiation-modified polyacrylonitrile fiber makes partial dehydrogenation reaction occurs, so the fiber heat resistance is improved by the modification, the exothermic peak moves to a lower temperature, heat release significantly reduced weight loss rate is more gentle heat, carbon income rate, which will slow the pre-concentration of the oxidation reaction heat, reducing pre-oxidation temperature, the more smoothly control the production, reduce energy consumption. In addition, the modified lower crystallinity of the fiber, the amorphous area increases, the oxygen content increased, the pre-oxidation process is conducive to the diffusion of oxygen, to promote the reaction. Use of the device for continuous carbon dioxide continuous PAN precursor of carbon dioxide was found that the pre-irradiation modified to decrease oxidation time 60min, reduced to one half of the original process, and the final strength of carbon fiber to form the relative increase of 23 %. Another use of dyeing machine PANF were chemically modified potassium permanganate. Potassium permanganate modification, infiltration inside the fiber cyano Mn7 ions form complexes with the carbon atom, reducing the cyano group of the molecular chain interaction, reducing heat release cyclization reaction, heat is relatively uniform. The infrared and X-ray diffraction analysis showed that the modified fiber structure generation with C = C, indicating that potassium permanganate can be catalyzed cyclization. In addition, the crystal structure of modified fiber is changed, the crystallinity is reduced, oxygen content increased with increasing modification time. Practice has proved that, potassium permanganate can be modified to some extent, to accelerate the pre-oxidation reaction rate, reduce the pre-oxidation time (75min-90min), the longer modified, the shorter the time the pre-oxidation, and the X-ray spectrum analysis showed that obtained pre-oxidized fiber skin-core structure is not obvious, sectional oxygen element distribution, so the relatively high mechanical properties, of which potassium permanganate modified by 5min 90min raw silk in the pre-oxidation, the final system had strength equivalent level of T300 carbon fiber. Finally method combines the two modified raw yarn pre-oxidation of a preliminary study found that this method may further reduce the pre-oxidation time, but the best solution for further study with a view to shortening the time of the pre-oxidized case, a significant improve the final properties of the carbon fiber.
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