on the occasion of his 70th birthday Emulsion polymerization is among the most important polymerization processes. [1] As a product, polymer latices that are stable colloidal aqueous dispersions of polymer particles of about 50 nm to 1 mm in size are obtained. About ten million tons annually of polymer latices are used for a variety of applications, such as environmentally friendly coatings and paints.
To date, polymer latices are produced industrially by freeradical polymerization exclusively. Styrene-butadiene copolymers, acrylate homo-and copolymers, and vinyl acetate polymers are the major industrial products. [1,2] The range of polymer microstructures accessible by free-radical polymerization and corresponding materials properties is limited. For example, the synthesis of dispersions of saturated inert polymers, which do not bear hydrolyzable groups is a challenge. [1] It is desirable to synthesize dispersions from simple olefins obtained directly from cracking of hydrocarbon feedstocks. This process would avoid the need to convert the cracked products to monomers such as acrylates or vinyl esters, which consumes energy and raw materials. [3] We and the group of Claverie have recently reported the synthesis and properties of polyethylene dispersions by catalytic polymerization in emulsion. [4][5][6] For traditional free-radical polymerization, the synthesis of very small particles is the subject of increasingly intense effort. [7, 8] Microemulsion polymerization is a particularly suitable, albeit special, technique. Latices of, for example, polystyrene particles as small as 10 nm diameter have been prepared by microemulsion polymerization. [8] A strong limitation is that microemulsions only form under specific