Method of preparing PAN-based carbon fibers

A method of preparing PAN-based carbon fibers, comprising the following steps:

• S1, mixing an acrylonitrile, a second monomer and an unsaturated UV-sensitive cross-linking agent, adding an initiator and performing a reaction to obtain a meltable PAN-based copolymer;
• S2, mixing a nano-reinforced material with the meltable PAN-based copolymer and a flow modifier to form a mixture, performing an extrusion and pelleting process on the mixture, further performing a melt spinning process to form nascent fibers, then performing a stretching and an annealing process on the nascent fiber to obtain a PAN-based carbon fiber precursor;
• the nano-reinforced material is 0-5.0% of a mass of the meltable PAN-based copolymer;
• the nano-reinforced material comprises at least one of MXene, carbon nanotubes, graphene, and graphene oxide;
• S3, performing an ultraviolet irradiation on the PAN-based carbon fiber precursor;
• S4, performing a pre-oxidization process and a carbonization process on the PAN-based carbon fiber precursor after ultraviolet irradiation to obtain PAN-based carbon fibers.