High-solid-content waterborne polyurethane and preparation method thereof

The invention relates to the field of polyurethane materials, in particular to high-solid-content waterborne polyurethane and a preparation method thereof. The high-solid-content waterborne polyurethane is prepared from the following components in parts by weight: 40 to 60 parts of isocyanates, 60 to 80 parts of polyols, 0.2 to 0.5 part of catalysts, 3 to 10 parts of alcohol chain extenders, 5 to 8 parts of amine chain extenders, 5 to 10 parts of hydrophilic chain extenders, 1 to 10 parts of micromolecule chain extenders, 1 to 3 parts of end-capping reagents, 3 to 5 parts of salt-forming agents, 30 to 50 parts of solvents and 100 to 200 parts of emulsifiers. Based on the characteristic that isocyanato of polyisocyanate can be subjected to Michael addition reaction with active groups such as hydroxyl, amido and water, a plurality of chain extenders are adopted to carry out chain extension addition reaction on a polyurethane prepolymer, and finally, the waterborne polyurethane with high solid content is prepared through neutralization and emulsification. In addition, the polyurethane is aqueous, so that the polyurethane is green and environment-friendly.