Based on the different precursors, carbon fibers can be classified into polyacrylonitrile (PAN)-based carbon fibers, pitch-based carbon fibers, and viscose-based carbon fibers. Among these, PAN-based carbon fibers have seen rapid development due to their relatively simple production process, mature production technology, and excellent comprehensive mechanical properties, accounting for approximately 90% of high-strength carbon fibers.
Polyacrylonitrile-based Carbon Fiber
PAN-based carbon fiber is prepared from polyacrylonitrile (PAN) fibers through pre-oxidation, carbonization, and graphitization treatments. This type of fiber has high strength, many grades, and high production volume (accounting for over 90% of total carbon fiber production). The higher the degree of order in the fiber's microstructure, the higher its strength and modulus. For example, T800 has a higher degree of order than T300, and its strength and modulus are also higher. The higher the degree of graphitization, the higher the elastic modulus.
Viscose-based Carbon Fiber
Viscose-based carbon fiber is a cellulose fiber produced from cotton or other natural fibers. It is obtained by low-temperature decomposition, carbonization, and graphitization treatment of viscose fibers. Viscose-based carbon fiber is mainly used in ablation-resistant materials, thermal insulation materials, and civilian electric heating products. It utilizes its well-developed and easily controllable porosity to manufacture activated carbon fiber products. While viscose-based carbon fiber accounts for less than 1% of total carbon fiber production, its unique properties make it irreplaceable.
Pitch-based carbon fiber
Pitch-based carbon fiber is prepared from pitch as a raw material through spinning, non-melting treatment, and carbonization. It exhibits high graphitization and high orientation, resulting in a higher elastic modulus than PAN matrix fibers. For example, the elastic modulus of pitch-based carbon fiber manufactured by Nippon Steel Corporation of Japan reaches as high as 784 GPa.
