| Abstract: | Kinetics of batch emulsion copolymerization of butyl acrylate (BuA) with methyl methacrylate (MMA) have been investigated using sodium dodecyl sulfate as emulsifier and the redox system potassium peroxodisulfate (K2S2O8)/sodium disulfite (Na2S2O5) as initiator. Latexes have been characterized with regard to their copolymer composition through 1H NMR analysis and particle size distribution by a quasi-elastic light scattering (QELS) technique or transmission electron microscopy. The effect of the monomer feed composition on the average copolymer composition vs. conversion was first studied in order to derive emulsion reactivity ratios. However, simulation of experimental data based on monomer partitioning (due to the high water solubility of MMA) and particle swelling was better accounted for when considering bulk reactivity ratios together with polymerization in the aqueous phase (in addition to that in the main locus of the polymer particles). Then, the influence of several pertinent parameters, such as emulsifier concentration, amount of initiator, monomer-to-water ratio and addition of an organic solvent has been examined in relation to the actual polymerization mechanism. |
