Transition Metal-Catalyzed Polymerization in Aqueous Systems - Late Transition Metal Polymerization Catalysis - page 230

Scheme 7.2 Free radical suspension, emulsion and miniemulsion
polymerization.

Film formation from a polymer latex upon evaporation of the dispersing medium. Scheme 7.3

Due to the kinetics of the polymerization in small particles, emulsion polymer-
ization allows for high polymerization rates and also high polymer molecular
weights at the same time. This differs from bulk free-radical polymerization,
where an increase in rate occurs at the expense of molecular weight and vice
versa. However, this is obviously a feature of classical free-radical polymeriza-
tion and must therefore not be considered further in the context of most transi-
tion metal-catalyzed polymerizations.

Polymer latexes possess a low viscosity by comparison to a solution of the poly-
mer in an organic solvent. During the polymerization process, this enables high
yields per reactor volume. The latex products can be handled readily, e.g. they
can be pumped. Also, many applications require a restricted viscosity. Polymer