Modified waterborne polyurethane dispersion as well as preparation method and application thereof

The invention relates to the technical field of waterborne polyurethane dispersions, and particularly discloses a modified waterborne polyurethane dispersion as well as a preparation method and application thereof. The modified waterborne polyurethane dispersion is prepared from the following raw materials in parts by weight: 10 to 20 parts of a composite material, 1.2 to 3.5 parts of polyhydric alcohol, 0.02 to 0.05 part of a catalyst, 0.01 to 0.05 part of a polymerization inhibitor, 1 to 5 parts of a neutralizing agent, 1 to 3 parts of a chain extender and 50 to 70 parts of water, and the composite material is prepared by modifying a polyurethane prepolymer by adipic dihydrazide; the preparation method comprises the following steps: uniformly mixing the composite material, the polyol, the catalyst and the polymerization inhibitor, heating, carrying out heat preservation to obtain a mixture, adding the chain extender, the neutralizer and water into the mixture, heating, and carrying out heat preservation to