Preparation of polymeric fluorosurfactants for dispersion polymerization in supercritical carbon dioxide

Abstract

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 common surfactants used in the conventional polymerization show negligible solubility in scCO2. Only the siloxane and fluorinated polymeric surfactants have been reported as successful stabilizers for the dispersion polymerization in scCO2. Therefore, this study focused on the preparation of new polymeric fluorosurfactants that can be utilized as effective steric stabilizers. And their stabilizing ability was tested in the dispersion polymerization of poly(methyl methacrylate) in scCO2.