Emulsion Polymerization

Emulsion polymerization is a useful technique for preparing waterborne latexes, which are the basis for many coating systems such as paints and inks. The polymerization reaction takes place in micelles in which the monomer droplet is stabilized by surfactants. The surfactants, usually an anionic or a combination of an anionic and nonionic surfactant, together with polymerization conditions, determine the particle size. Anionic surfactants provide shear stability to prevent loss due to coagulation. Nonionic surfactants provide electrolyte or chemical stability to the growing latex particles. The type and structure of a surfactant can have a dramatic effect on emulsion properties such as particle size, particle size distribution, and latex viscosity.