| 초록 |
Recently, supercritical CO2 is becoming an alternative medium to liquid solvents traditionally employed in polymerization since it is environmentally benign, inexpensive and non-flammable. In addition, it has easily attainable critical conditions (Tc=304.25K, Pc=73.8 bar). Unique properties of the supercritical CO2 such as large solubility and high mass transfer rates provide advantages in dispersion polymerization of various kinds of monomers. And the desired products can be easily separated from monomers and solvents simply by changing the pressure of CO2. But unfortunately, most industrially used hydrocarbon surfactants are insoluble in supercritical CO2. Only the siloxane and fluorinated polymeric surfactants such as PDMS and PFOA have been reported as successful stabilizers for the dispersion polymerization. We prepared the newly designed polymeric fluorosurfactants that can be utilized as effective steric stabilizers, which were tested in the dispersion polymerization of PMMA. We study the structural effect of the fluorosurfactants to the dispersion polymerization in supercritical CO2 and the preparation of polymer particles using these fluorosurfactants. |
