Particle size and hydrolysis resistance: The stability of the emulsion is closely related to the particle size and hydrolysis resistance of the polyurethane particles. The smaller the particle size, the better the stability of the emulsion. The poor hydrolysis resistance will cause the emulsion to degrade slowly during the storage process, produce carboxyl group, reduce pH value, and make the emulsion condense.

Degree of neutralization: The degree of neutralization refers to the degree of reaction between the neutralizer and the carboxyl group. With the increase of the neutralization degree, the particle size of the emulsion decreases and the viscosity increases, which is helpful to improve the stability of the emulsion. However, too high a degree of neutralization will cause the viscosity of the emulsion to be too high, but reduce the stability.

PH value: Fluctuations in pH value can affect the stability of the emulsion. An acidic or alkaline environment will cause the emulsion to coagulate. Therefore, controlling the right pH range is essential to maintain the stability of the emulsion.

Storage conditions: High and low temperatures should be avoided during storage, as these conditions will cause the emulsion to condense and affect its stability.

Solid content and drying speed: The low solid content of waterborne polyurethane will lead to increased drying and transportation costs, and the drying speed is slow, affecting its stability. In addition, the increase of solid content and crosslinking degree will also reduce the storage stability of the emulsion.

Methods to improve the stability of waterborne polyurethane emulsions include:

Particle size control: By adjusting the preparation process, the particle size of polyurethane particles is controlled within a reasonable range to improve the stability of the emulsion.

Improve the solid content and drying speed: By improving the production process, improve the solid content, and optimize the drying conditions to improve the stability and use efficiency of the emulsion.

Anhui Sinograce Chemical Co., Ltd. to do waterborne polyurethane. We have water based polyurethane for leather, water borne polyurethane for coatings, water based polyurethane for adhesives, waterborne polyurethane for inks, and various types of water based pu resins. Welcome to consult.