MICROEMULSION POLYMERIZATION OF BUTYL ACRYLATE .3. EFFECT OF THE MONOMER CONCENTRATION

The oil-in-water (o/w) microemulsion polymerizations of butyl acrylate initiated with a water-soluble (ammonium peroxodisulfate, AP) and/or an oil-soluble (dibenzoyl peroxide, DBP) radical initiator at different monomer feed compositions and monomer concentrations were investigated. The rate of polymerization shows nucleation and termination intervals. The rate of polymerization is found to increase with the BA concentration. The polymerization is faster with AP than with DBP. The average number of radicals per particle increases exponentially with both the monomer concentration and the particle size. The number of particles decreases with monomer concentration. The molecular weights parallel the rate of polymerization and are larger in the systems with DBP.