No abstract

The present study evaluated the fabrication of methyl methacrylate-based polymer nanoparticles by miniemulsion and combined miniemulsion/emulsion polymerization using an atomization apparatus with two-fluid nozzle. In both reactions, the effects of the operational conditions were investigated on the morphology and particle size distribution of polymer particles. After multivariate analysis, it was observed that the size of the poly(methyl methacrylate) particles is a function of gas pressure in the experiments stabillized by sodium lauryl sulfate (SLS), but this did not occur in reactions stabillized by inorganic and polymeric stabilizers. The use of inorganic stabilizer made possible the fabrication of polymer particles smaller than 300 nm. In combined miniemulsion/emulsion polymerization with SLS, high concentrations of surfactant (> 0.4% w/w) and intermittent monomer feeding enabled not only an increase of the solid concentrations, but also a reduction of particle size. In addition, styrene-methyl methacrylate nanoparticles were successfully obtained (< 30 nm), according to dynamic light scattering and transmission electron microscopic analyses.