Surfactant-Free Synthesis of Polystyrene Nanoparticles Using Oligoglycidol Macromonomers

We investigate the synthesis of functional polystyrene/oligoglycidol particles by surfactant-free emulsion polymerization. Oligoglycidol macromonomers with linear and branched oligoglycidol structure and variable oligoglycidol chain lengths were synthesized. These macromonomers were used as surfmers (surfactants and comonomers) in emulsion polymerization of styrene. Monodisperse colloidally stable polystyrene particles were obtained, decorated with oligoglycidol chains with diameters between 100 and 600 nm. The increase of the macromonomer concentration induced a decrease of the particle size and broadening of the particle size distribution. The macromonomers with branched architecture were more effective and produced monodisperse particles even at low concentrations. Due to the steric stabilization provided by the hydrophilic oligoglycidol layer on the particle surface, the emulsion of polystyrene/oligoglycidol particles obtained exhibited very good resistance against electrolytes. The chemical and enzyme catalyzed grafting polymerization of ε-caprolactone from the polystyrene/oligoglycidol particle surface was demonstrated along with formation of composite particles.