(84g) The Purification of Polymeric Microspheres Via Soxhlet Extraction Using Liquid DME

Polymer particles, used in cosmetic, pharmacy, and electric uses, require the purification for the removal of un-reacted monomer and residual surfactant used for the synthesis. For the purification of the synthesized polymer particle, the extraction using the organic solvent or supercritical fluid as a solvent was applied. In case of the organic solvent, the use of such common organic solvents, though, has been associated with several problems, including waste treatment and product separation disadvantage. Especially, the removal of amorphous fluorine-base polymer surfactants, the fluorinated or chlorinated solvents, such as CFCs and hexafluoro isopropyl alcohol, were used. Theses solvent cause not only waste treatment problem, but also ozone depletion. In case of supercritical fluid, especially scCO₂, high-pressure operating pressure, over 310 bar, causes the necessary apparatus to be quite costly. In an effort to circumvent these issues, the Soxhlet extraction using liquid DME was conducted. In this study, the Soxhlet extraction using liquid DME was conducted for on the removal of surfactants, siloxane-based surfactant and fluorine-based surfactant. After the extraction, the morphology was checked using FE-SEM and the residual concentration of surfactants was analyzed using EDS. Compared with n-hexane and liquid CO₂, liquid DME produced the more extracted microspheres than others produced. The residual surfactant concentration of the extracted microspheres was decreased dramatically.