High-steric-hindrance urea bond-containing curing agent as well as preparation method and application thereof

The invention discloses a curing agent containing a large-steric-hindrance urea bond as well as a preparation method and application of the curing agent. The method mainly comprises the following steps: dissolving bifunctional aromatic amine and alkali in a solvent, adding halogenated hydrocarbon at 70-85 DEG C, and reacting for 8-12 hours to obtain an intermediate product secondary amine; the preparation method comprises the following steps: adding diol and an anhydrous solvent into bifunctional isocyanate, and reacting at 50-60 DEG C for 2-6 hours to obtain a polyurethane prepolymer; and adding secondary amine and an anhydrous solvent into the polyurethane prepolymer, and reacting at 50-60 DEG C for 6-8 hours to obtain the large-steric-hindrance urea bond-containing curing agent. The prepared curing agent containing the large-steric-hindrance urea bonds can overcome the defects of other dynamic covalent bonds, and epoxy resin prepared based on the curing agent containing the large-steric-hindrance urea bond