The characterization of PAN-based carbon fibers developed by two-stage continuous carbonization

Abstract

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°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°C and 700°C, had better Young's modulus. Experimental results using a X-ray diffractometer indicated the presence of a less ordered phase at 2 Θ = 17° in the precarbonized fibers and the final carbon fibers. The formation of this less ordered structure is also discussed.