Precise control of monodispersed PMMA microspheres by soap-free emulsion polymerization

The effects of methanol and ionic comonomer amounts on the particle size have been studied in soap-free emulsion polymerization of methyl methacrylate. The particles were uniformly dispersed below 20 wt% of methanol content and the particle size decreased with decrease in methanol content. The particles were monodispersed regardless of the ionic comonomer/methyl methacrylate ratio and the particle size decreased with increase in ionic comonomer concentration. These added components would contribute to the monomer solubility and the stability of the formed particles. We have thus succeeded in controlling the particle size from 100 nm to 1 mu m by the content of methanol and that of the ionic comonomer.