The Preparation of High Performance Carbon Fibers Developed from Stepwise Stabilization Process

By the dynamic viscoelastic property, we can understand the molecular motion of the PAN fibers during the heat stabilization process and find that the ladder polymers are formed at temperature above 200°C. The ladder polymers are formed quickly when the PAN fibers are treated by the stepwise stabilization process. The ladder polymers developed from the modified PAN fibers are formed earlier than those developed from the original PAN fibers but the growth rate of the former is slower and milder. The strength of the carbon fibers developed from the stepwise stabilization process is more than 3.3 GPa. By using the modified PAN fibers instead of the original ones as the precursor, the strength can further raise 20-30%.