The invention provides a waterborne
polyurethane emulsion as well as a preparation method and application thereof. The waterborne
polyurethane emulsion is prepared from the following raw materials: abio-based emulsifier, diisocyanate, a first chain
extender, a second chain
extender, a salt-forming agent, a
viscosity reducer and deionized water. The bio-based emulsifier is used as a preparation
raw material for the first time, and the bio-based emulsifier not only contains hydroxyl capable of reacting with
isocyanate radicals, but also contains carboxyl capable of generating salt forming reaction, therefore, requirements of a traditional waterborne
polyurethane emulsion preparation process on catalysts and organic solvents are avoided, and consumption of hydrophilic chain extenders can bereduced, besides, the bio-based emulsifier is used as a
soft segment in polyurethane molecular chains, and the molecular structure of the bio-based emulsifier contains carboxyl, so that the particle size of the waterborne polyurethane emulsion is reduced, and the
dispersity and stability of particles are improved. The preparation method is simple and easy to operate, no
solvent or catalyst is usedin the whole preparation process, and the preparation method is more
environmentally friendly.