Preparation of Polymer/Poly(ionic liquid) Composite Particles by Seeded Dispersion Polymerization

Seeded dispersion polymerization of the ionic-liquid monomer ([2-(methacryloyloxy)ethyl]trimethylammonium bis(trifluoromethanesulfonyl)amide) ([MTMA][TFSA]) was performed in ethanol by using either polystyrene (PS) or poly(methyl methacrylate) (PMMA) particles as seeds. In the presence of PS seed particles, secondary nucleated poly(ionic liquid) (PIL) particles were formed, and no PS/PIL composite particles were observed. In the case of PMMA seeds particles, the diameters of the obtained particles increased compared to those of PMMA seed particles (without formation of particles that were formed as byproducts), which indicates that the PMMA/PIL composite particles were successfully prepared. Transmission electron microscopy studies of ultrathin cross sections of the PMMA/PIL particles revealed that the obtained particles had a sea-island structure consisting of PIL domains. These results are consistent with the theoretical considerations based on the spreading coefficients calculated from the interfacial tensions.