The issue of excessive oily components in water-based polyurethane emulsions
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The water-based polyurethane emulsion I used had a high oil content; after application, it left oily spots all over the surface, resulting in defects that made the product unusable. I would appreciate it if someone could explain the components of the oily emulsifiers used in its synthesis
An oil-based liquid of lipophilic surfactants interacts with the oil in the penetrating solution, making it easy to wash away with water.
An emulsifier is a substance that can reduce the surface tension between the various components in an emulsion, thereby enabling the formation of a uniform and stable dispersion or emulsion. Emulsifiers are surfactants whose molecules possess both hydrophilic and lipophilic groups. They gather at the oil/water interface, where they can reduce interfacial tension and the energy required to form an emulsion, thereby increasing the stability of the emulsion. All emulsifiers contain two functional groups in their molecules: a hydrophilic group that can attract water layers, and an lipophilic group that can surround oil layers. Therefore, by adding an emulsifier to the oil-water system, water and oil can mix with each other to form a fully dispersed emulsion. However, the hydrophilicity and lipophilicity of emulsifiers are generally unbalanced, and the applications suitable for them also differ. Generally, emulsifiers with high hydrophilicity are suitable for O/W emulsions, while those with high lipophilicity are suitable for W/O emulsions