Study On The Modification And Carbonization Behavior Of Coal Tar Pitch

Coal tar pitch as raw materials, through pretreatment, modified, preoxidation, carbonization or graphitization, carbonization fiber was obtained.Extracted by quinoline, coal tar pitch was heated in nitrogen to prepare a modification of coal tar pitch, in the presence of boron fluoride ethyl ether and nitrobenzene as a catalyst. The characteristic of the modified of coal tar pitch was studied. FT-IR, TGA, rheometer and elemental analyzer were performed to study on the modified of coal tar pitch. The result showed that condensation temperature of350℃for1h was the best process conditions, and modified coal tar pitch with reducing aliphatic side chains and weight loss rate and increasing aromatization can be used for the preparation of carbon fiber. The temperature of preoxidation is350℃. There was a huge rang area of low viscosity and well-spinnable for modification of coal tar pitch at200℃and the dependency on the temperature reduced. The results showed that the C/H value increased, the H elements decreased in product, and the reaction of thermal condensation is dehydro-condensation reaction.Through melt-spinning, preoxidation and carbonization, carbonization fiber was obtained. Affecting the carbonization behavior of the modified carbon fiber from cross-sectional area and the temperature of carbonization were studied. Digital camera, SEM, TEM, XPS and elemental analyzer were performed to study on carbon fiber. The results showed that the rough surface of carbon fiber increased as cross-sectional area increased. More uniform microstructures and high mechanical properties of carbon fiber obtained at carbonization temperature of800℃for2h. Carbon fiber with a graphite crystallite structure was obtained at carbonization temperature of900℃for2h, and the mechanical properties was decreased.