Preparation method of high-solid-content waterborne polyurethane

The invention relates to the field of polyurethane preparation, in particular to a method for preparing high-solid-content waterborne polyurethane in one step. Hydrophilic groups based on waterborne polyurethane soft segments are mainly located in waterborne polyurethane colloidal particles, bound water is formed in the waterborne polyurethane colloidal particles and is closer to polyurethane without hydrophilic groups, the regularity of a polyurethane hard segment region chain structure is not damaged, and the situation that more bound water is formed on the surfaces of the waterborne polyurethane colloidal particles, so that the viscosity of emulsion is increased is avoided; the water-based polyurethane with the solid content of 60-74% is prepared, and the average particle size of the prepared water-based polyurethane emulsion is 100-700 nm. The method is simple and easy to implement, and solves the problems of high transportation cost, low drying and film-forming speed, low equipment utilization rate, high