RAFT POLYMERIZATION AND SUPERCRITICAL CARBON DIOXIDE

摘要

First, reversible addition-fragmentation chain transfer (RAFT) polymerization of 1,1,2,2-tetrahydroperfluorodecyl acrylate (FDA) has been performed in trifluorotoluene in the presence of a dithioester based on poly(ethylene oxide) (PEO) as reversible chain transfer agent to prepare PEO-b-PFDA (hydrophilic/CO_2-philic) block copolymers. The solubility behavior of such macromolecular surfactants has been studied by determination of the cloud point curve in neat supercritical CO_2. Second, supercritical CO_2 has been used as the reaction medium for RAFT polymerization of 1,1-dihydroperfluorooctyl acrylate (FOA) (solvent free high pressure living radical polymerization). For both PEO-b-PFDA block copolymers and PFQA homopolymers, high yields were obtained and the living character was checked by quantitative UV analysis of the dithiobenzoyl end group of the polymer chains.