Acrylic acid is a commonly used internal crosslinking agent. It can not only improve the cohesive strength of the polymer and endow the emulsion with excellent alkali thickening properties, but also play a stabilizing role in the system. However, when the temperature is lower than 14°C, acrylic acid changes from liquid to solid state, resulting in insufficient mixing in the pre-emulsion.

The emulsifier is not fully dissolved, resulting in insufficient pre-emulsification. The solution is to heat the pre-emulsification components to 50 - 60°C with water before pre-emulsification. Meanwhile, appropriately prolong the stirring time and intensity during the pre-emulsification process.

There are iron or copper components in contact with the reaction solution, and metal ions interfere with the reaction.

There is a problem with the water quality. Softened water should be used, and deionized water is preferred.

There are flaws in the emulsion system design, resulting in the occurrence of "bald spots" locally in Stage II. Optimize the emulsion system or switch to a new formulation.

Phase separation caused by low temperature: In winter, the temperature is relatively low, and the polymer particles in the emulsion may undergo phase separation due to the low temperature. Emulsion is usually a multiphase system, including polymer phase, water phase and other additives. At low temperatures, the solubility of the polymer decreases, and the interaction between polymer particles changes. The originally uniformly dispersed polymer particles may aggregate or precipitate, changing the microstructures of the emulsion. When light shines on these emulsions with phase separation, special optical phenomena may occur, such as green light or iridescence.