THE CHARACTERIZATION OF PAN-BASED CARBON-FIBERS DEVELOPED BY 2-STAGE CONTINUOUS CARBONIZATION

A continuous stabilization and two-stage carbonization process was used to prepare polyacrylonitrile (PAN)-based carbon fibers. The effect of precarbonization on the final properties of carbon fibers was measured. The results of this study showed that a suitable precarbonization was very conducive to improvement in tensile strength or in Young's modulus of the final carbon fibers. When the final carbon fiber was precarbonized at 550-degrees-C, this fiber had a higher tensile strength than carbon fibers which were precarbonized at other conditions. On the other hand, the final carbon fibers developed at precarbonization temperatures of 650-degrees-C and 700-degrees-C, had better Young's modulus. Experimental results using a X-ray diffractometer indicated the presence of a less ordered phase at 2THETA = 17-degrees in the precarbonized fibers and the final carbon fibers. The formation of this less ordered structure is also discussed.