초록 |
We have been carrying out investigations on the synthesis of functional polymer particles by emulsion polymerization, dispersion polymerization, and seeded polymerization in aqueous media from the viewpoint of the concept of “particle design”. Moreover, in addition to water, supercritical carbon dioxide (scCO2) has emerged as a promising replacement of volatile organic solvents. The use of scCO2 as a medium has several potential advantages. It is nonflammable, nontoxic, inexpensive and easy to remove from the polymerization mixture. We recently reported the preparation of poly(methyl methacrylate) particles by dispersion polymerization in scCO2 as medium. Another trend of late has been to make use of ionic liquids, which are salts that melt at ambient temperature, for electrochemical and separations processes and as media for chemical and biochemical synthesis. The unique properties of ionic liquids are exemplified by their behavior as solvents as well as by their ability to sometimes influence reaction rates. Ionic liquids are considered environmental friendly solvents due to their low vapor pressures, chemical and thermal stabilities, and non-flammability. We have succeeded in preparing polystyrene particles by dispersion polymerization in an ionic liquid, N,N-diethyl-N-methyl-N-(2-methoxyethyl) ammonium bis(trifluoromethanesulfonyl) imide ([DEMMA][TFSI]) for the first time. |