General Aspects of Emulsion Polymerization

Emulsion polymerization involves the emulsification of monomers in an aqueous phase, and stabilization of the droplets by a surfactant. Usually, a water-soluble initiator is used to start the free-radical polymerization. The final product is a dispersion of submicrometer polymer particles, which is called latex. The locus of polymerization is the micelle. Typical applications are paints, coatings, adhesives, paper coatings and carpet backings. The latex particles can have different structures (see Fig. 2). Excellent text books on the applications and structure-property relationships exist [11-15]. Besides a full description of the kinetics and mechanism of emulsion polymerization [16], a textbook adapted for use as material for people entering the field is also available [17]. 

In emulsion polymerization, one can achieve relatively high rates of polymerization and high molar masses as compared to, for example, solution polymerization. 

One of the first major applications of latex was the replacement of natural rubber latex by synthetic rubber latex during the Second World War. From there, a continuing interest in the preparation of lattices has evolved. At the end of the twentieth century, environmental aspects are starting to play a role in the further introduction of emulsion polymerization techniques, replacing solvent-based polymerization processes. 

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