Preparation method of anionic waterborne polysulfide ammonia ester

The invention discloses a preparation method of anionic waterborne polysulfide ammonia ester. The method includes the following steps of mixing liquid polysulfide rubber with isocyanate, making the mixture react to synthesize monoisocyanate-terminated polysulfide modified polyurethane prepolymer, conducting chain extension reaction on the monoisocyanate-terminated polysulfide modified polyurethane prepolymer, a small-molecule chain extender, an anionic hydrophilic chain extender and a crosslinking agent to obtain isocyanate-terminated polysulfide modified polyurethane, and emulsifying the isocyanate-terminated polysulfide modified polyurethane to obtain anionic waterborne polysulfide ammonia ester dispersoid. Obtained anionic waterborne polysulfide ammonia ester resin is excellent in environment protection performance, can be used in cooperation with alkaline resin and neutral resin, is high in strength, excellent in wear resistance, adhesion force and flexibility, good in compactness, high temperature and lo