Initiator systems in miniemulsion polymerization for preparation of magnetite/acrylic particles

Miniemulsion polymerization is an appropriate system for encapsulation of magnetite nanoparticles. In this work, modified Fe3O4 nanoparticles were prepared and copolymerized with methyl methacrylate (MMA), butyl acrylate (BA) and acrylic acid (AA) through miniemulsion polymerization. The polymerization was performed in the presence of sodium dodecyl sulfate as ionic surfactant, Tween-80 as non-ionic surfactant, sodium bicarbonate as buffer and hexadecane as hydrophobe. The key point in achievement of encapsulation of modified Fe3O4 nanoparticles was the preparation of a stable latex at the end of the reaction. To achieve this purpose, several initiators were used. The best system was BPO/DMA as a redox initiator system at low conversion of monomers. To increase monomer conversion, the polymerization was subsequently continued by adding another redox system including TBPB/SFS/EDTA/FeSO4 to obtain a stable latex with high conversion (98%). Finally, the samples were characterized by FTIR, TGA, DLS and VSM analyses