▎ 摘　　要

NOVELTY - Preparing a graphene / polyacrylonitrile spinning stock solution involves adopting aqueous phase suspension polymerization process. The material composed of the third monomer, initiator, regulator, molecular weight regulator, polymerization accelerator, and reaction medium is added to the polymerization kettle, and after polymerization and termination, a polymer slurry is obtained. The first monomer is acrylonitrile (AN), the second monomer is methyl acrylate (MA) or vinyl acetate (VAC), the third monomer is sodium methacrylic acid (MAS), the initiator is sodium chlorate and sodium metabisulfite. The mass percentage of the first, second and third monomers is 34%. The mass percentage of the third monomer is 0.23 wt.%, and the mass percentage of sodium chlorate in the initiator is 0.50 wt.%. The molar ratio of sodium metabisulfite to sodium chlorate is 1.5, and the mass percentage of the molecular weight regulator is 0.22 wt.%. USE - Method for preparing a graphene/polyacrylonitrile spinning stock solution. ADVANTAGE - The method enables to prepare a graphene/polyacrylonitrile spinning stock solution, which provides a good basis for further preparing graphene / polyacrylonitrile fibers with low specific resistance and high tensile breaking strength and is suitable for industrial production. DETAILED DESCRIPTION - The polymerization time is 52 to 55 minutes, the polymerization temperature is 55 to 60 degrees C, and the polymerization pH is 2.0. The polymer slurry is sequentially sent to a de-separation tower, a first condenser, and a second condenser for de-separation. The polymer slurry after de-separation is sent to a storage tank to stay, and then the polymer slurry is washed with water and adjusted for concentration, fed into the rotary filter from the bottom to obtain a polyacrylonitrile filter cake with a water content of 45-50 wt.%. The polymer slurry flows countercurrently with steam during de-singing, the bottom temperature of the single-separating tower is 85 degrees C, and the temperature of the top of the single-separating tower is 74 degrees C. The order removal is carried out in a vacuum environment, the absolute pressure is 50.7 ~ 58.0kPa. The condensing medium in the first condenser is water, the temperature is 68 ~ 72 degrees C. The condensing medium in the second condenser is water and the temperature is 7 degrees C. The residence time of the polymer slurry in the storage tank is more than one hour. The polyacrylonitrile filter cake is blown away from the rotary filter by air after washing the polyacrylonitrile filter cake. A polyacrylonitrile slurry with a polyacrylonitrile concentration of 34.7% is obtained and sent to a storage tank for storage. The washing water used for washing is pure water, the temperature is 48 ~ 62 degrees C. The vacuum degree during washing is 53-60kPa. The air pressure used for blowing away is 0.02MPa. A certain amount of graphene powder is added to the NaSCN solution with a mass percentage of 58%. The high shear mixer is used to quickly stir and disperse, the speed is 5000 revolutions per minute, the time is 1 hour. A graphene-NaSCN solution with a graphene mass percentage of 10% is obtained. The material composed of the solution, the concentrated NaSCN solution, the polyacrylonitrile slurry and the sodium metabisulfite solution is sent to a high-shear dissolver for dissolution to obtain a crude stock solution. The mass fraction of NaSCN in the concentrated NaSCN solution is 58 wt.%, the feed volume ratio is automatically cascade controlled by the DSC instrument, the temperature of the concentrated NaSCN solution is 85 degrees C, and the dissolution temperature is 74 degrees C. The crude stock solution has 11.50 wt.% polyacrylonitrile, 1.0-4.0 wt.% graphene, 38.6 wt.% NaSCN. The outlet pressure of the high-shear dissolver is 0.05-0.08MPa. The crude stock solution is heated to 76 degrees C, and then sent to the defoaming tower for defoaming. The degassing process uses temperature difference control, the temperature difference is set to 22 degrees C, the degassing vacuum is 6.7 ~ 8.2kPa. The defoaming tower liquid level is controlled by frequency conversion to control the speed of the defoaming tower pump. After heating and filtering the crude stock solution, a graphene / polyacrylonitrile stock solution is obtained. The graphene / polyacrylonitrile stock solution has 11.80 wt.% polymer, 1.0-4.0 wt.% graphene, 39.6 wt.% NaSCN, and the viscosity is 2000CP (at 54 degrees C). A two-step process of aqueous phase suspension polymerization and dissolution of polyacrylonitrile resin with an inorganic solvent are adopted.