Photopolymerization of alkyl(meth)acrylates and polyoxyethylene macromonomers in fine emulsions

The kinetics of radical polymerization and copolymerization of alkyl(meth)acrylates with and without polyoxyethylene macromonomers in fine emulsions photoinitiated by a UV light was investigated. The fine monomer emulsions were formed in the presence of high amount of emulsifier without any homogenization. The rate of polymerization with ethyl acrylate was larger than that with methyl methacrylate or nonyl methacrylate. The addition of PEO-MA macromonomer decreases the rate of polymerization and the molecular weight as well. The rate-conversion curve showed four regions with two rate maxima ca. at 5–20% and 50–70% conversion in which the first maximum was much more pronounced than the second one. The results were discussed in terms of polymerization within fine microdroplets. The particle number increased with increasing alkyl group of monomer. The particle size distribution was observed to increase from NMA, via EA to MMA. The polymer molecular weights were inversely proportional to the particle size.