Emulsion polymerization of methyl methacrylate initiated by alkene ozonates

Abstract

Ozonolysis of tetramethyl ethene, trans-4-octene or 1-octene in water leads to species, which after thermolysis at 60°C, generate radicals that initiate radical emulsion polymerization of methyl methacrylate (MMA). The course of the reaction is dependent on the structure of the alkene used. Tetramethyl ethene ozonates give the highest final yield of polymer, although the rates of polymerization observed from 0 to approximately 60% conversion are found to be essentially equivalent, regardless of the structure of the alkene employed. The difference in final conversion is attributed to changes in the half life of the generated peroxy species as a function of alkene structure. From these differences it is inferred that the initiating species are organo peroxides, probably hydroxy hydroperoxides, rather than hydrogen peroxide. Two latex systems, one stabilized by a cationic surfactant and the other by an anionic surfactant, were successfully prepared. Ozonolysis of water followed by heating in the presence of MMA does not produce polymer. However, ozonolysis of an aqueous sulphonate surfactant solution does produce a species that forms radicals on thermolysis and these radicals initiate radical polymerization of MMA, which proceeds to high conversion in emulsion.