The preparation and polymerization of monomers in microemulsion systems were previously reported. Phase diagrams of microemulsions containing copolymerizable surfactant and/or cosurfactant are presented with others developed in this series. Investigations into the structures of polymers prepared from microemulsified monomers has revealed that droplet size is in the macroemulsion size region, thus explaining problems encountered with phase separation. It is not known whether droplet size growth is an unavoidable natural consequence of the polymerization mechanism or purely a result of unstable starting compositions resulting from higher temperatures used for initiation.