Synthesis and characterization of polymer networks obtained by conventional radical and RAFT copolymerization processes in supercritical carbon dioxide

Abstract The syntheses of net ‐poly((2‐hydroxyethylene methacrylate)‐ co ‐(ethylene glycol dimethacrylate)), abbreviated as net ‐poly(HEMA‐ co ‐EGDMA), by conventional (FRP) and reversible addition‐ fragmentation chain transfer (RAFT) radical copolymerizations using supercritical carbon dioxide as green solvent at different pressures are reported. The effect of pressure on the characteristics of the produced polymer networks is emphasized. A comparison between the two synthetic routes (FRP vs. RAFT) in terms of measurements of swelling index, scanning electron microscopy including determination of particle size distributions, modular differential scanning calorimetry to obtain glass transition temperatures, and thermogravimetric analyses in their differential form is presented. Not only were the differences in the characteristics of the obtained polymer networks explained, but the mechanism of particle formation and the final morphologies of the samples were also elucidated.