▎ 摘　　要

NOVELTY - Reduction of graphitization temperature of polyacrylonitrile carbon fiber involves mixing suspension of graphene quantum dots and dispersion of polyacrylonitrile, stirring, defoaming, obtaining graphene quantum dots-modified polyacrylonitrile, subjecting to wet spinning or dry-jet wet spinning, obtaining graphene quantum dots-modified polyacrylonitrile fiber, pre-oxidizing, low-temperature graphitizing, low-temperature carbonizing, high-temperature graphitizing, and obtaining polyacrylonitrile/graphene quantum dot carbon fiber having high strength and high modulus. USE - Reduction of graphitization temperature of polyacrylonitrile carbon fiber (claimed). ADVANTAGE - The method enables efficient and reliable reduction of graphitization temperature of polyacrylonitrile carbon fiber. The breaking strength and elasticity modulus of carbon fiber is improved by 5-20% and 10-30%, respectively. The graphitization temperature of polyacrylonitrile carbon fiber is reduced to 80-400 degrees C. DETAILED DESCRIPTION - Reduction of graphitization temperature of polyacrylonitrile carbon fiber involves adding 1-12 %mass graphene quantum dots to solvent (B), mixing, obtaining suspension of graphene quantum dots, adding polyacrylonitrile powder to solvent (A), heating at 40-75 degrees C for 24-72 hours, stirring, obtaining uniform dispersion of polyacrylonitrile, mixing suspension of graphene quantum dots and dispersion of polyacrylonitrile, stirring at 20-75 degrees C for 1-24 hours, defoaming at 45-75 degrees C for 12-24 hours, obtaining graphene quantum dots-modified polyacrylonitrile, subjecting to wet spinning or dry-jet wet spinning, obtaining graphene quantum dots-modified polyacrylonitrile fiber, pre-oxidizing at 180-300 degrees C for 0.5-2 minutes, obtaining product (a), low-temperature graphitizing product (a) at 450-950 degrees C, low-temperature carbonizing for 0.5-2 minutes, obtaining product (b), high-temperature graphitizing product (b) at 1300-1900 degrees C for 0.3-2 minutes, and obtaining polyacrylonitrile/graphene quantum dot carbon fiber having high strength and high modulus. The content of graphene quantum dots based on amount of polyacrylonitrile is 0.1-5 %mass. The graphene quantum dots-modified polyacrylonitrile contains 0.1-5 pts. wt. graphene quantum dots and 100 pts. wt. polyacrylonitrile. The total amount of solvent (A) and solvent (B) is 203.2-945 pts. wt.