Preparation method of ternary copolymerized amphoteric polyacrylamide

The invention belongs to the technical field of flocculant preparation, and relates to a preparation method of ternary copolymerized amphoteric polyacrylamide, wherein the preparation method comprisesthe steps: firstly, preparing a novel cationic monomer AHPTAC, mixing and dissolving the monomer with other two monomers of AM and AMPS, deoxidizing, then adding an initiator, heating up, after a reaction is completed, cooling, dropwise adding the obtained water dispersed system into absolute ethyl alcohol, precipitating, washing, filtering and drying, and crushing to obtain a white solid product. The total mass of the three monomers is 20% of the total mass of the system, and the molar ratio of AM to AHPTAC to AMPS is 1 to 3 to (1-4); the initiator is one or two of VA-044 and ammonium persulfate-sodium bisulfite; the adding amount of the initiator is 0.2% of the total mass of the three monomers. The preparation method is simple to operate, and the prepared ternary copolymerized amphoteric polyacrylamide has high