Antibacterial anionic waterborne polyurethane containing sophocarpidine and preparation method thereof

The invention discloses a preparation method of antibacterial anionic waterborne polyurethane containing sophocarpidine, which comprises the following steps: reacting polyether polyol or polyester polyol with a hydrophilic chain extender, a micromolecular chain extender and binary isocyanate to obtain a polyurethane prepolymer, salinizing by using a salt-forming agent containing antibacterial alkaloid, emulsifying, and carrying out chain extension to obtain the antibacterial anionic waterborne polyurethane containing sophocarpidine. And removing the solvent to obtain the antibacterial waterborne polyurethane. Matrine which is wide in source, good in antibacterial property and safe to human bodies is selected as an antibacterial agent and a salt-forming agent at the same time, and a matrine quaternary ammonium salt antibacterial component is directly introduced into waterborne polyurethane through a chemical modification method for forming ionic bonds. Compared with a physical blending method and a covalent bo