Polyaddition in miniemulsions: A new route to polymer dispersions

Polyaddition reactions in miniemulsions were successfully performed by mini emulsification of mixtures of di-, tri-, and tetra-epoxides with varying di amines, dithiols, or bisphenols, and subsequent heating to 60 degrees C. Th is expands the potential applications of the family of miniemulsification t echniques to generate aqueous polymer dispersions, since miniemulsions were previously just employed for the radical polymerization of vinylic monomer s. Depending on the chemical nature of the monomers, the amount of surfacta nt, and the pH of the reaction mixture, latex particles with diameters betw een 30 and 600 nm and sometimes very narrow particle size distributions wer e obtained. Gel permeation chromatography (GPC) measurements on the final polyaddition products reveal molecular weights of about 20 000 with a polydispersity ind ex df close to 2, i.e., close to ideal reaction conditions are preserved th roughout the heterophase reaction.