Microemulsion Polymerization of Methyl Methacrylate Initiated With AIBN

Methyl methacrylate microemulsion was stabilized with 12 butinyoxyl 9 octadecenoic acid (BOA), and the microemulsion with 20% MMA remained clear when it was initiated with AIBN. Through observing the variation of the polymer particle size, it was found that when conversion was lower than 30%, the polymerization occurred in the large polymer particles swollen with monomer. While at higher conversion, the monomer swollen micelles became the main loci of polymerization, and the number of total particles increased rapidly by about 20 times. The polymerization kinetics of MMA microemulsion initiated with AIBN was quite different from that of nonpolar monomer microemlsion initiated with AIBN.In the case of MMA, increasing the emulsifier content in the microemulsion led to the decrease of the rate of polymerization, due to the dilution of concentrations of monomer and initiator in the polymerization loci, while for nonopolar monomers, the rate of polymerization increased with the increase of emulsifier content.