Effect of Stabilizer Concentration, Pressure and Temperature on Polymerization Rate and Molecular Weight Development in RAFT Polymerization of MMA in scCO2

An experimental study on the effect of stabilizer concentration, pressure (100 to 500 bar), and temperature (65 to 85 °C) on polymerization rate and molecular weight development in the reversible addition‐fragmentation chain transfer (RAFT) polymerization of methyl methacrylate (MMA) in supercritical carbon dioxide (scCO2) is presented. AIBN was used as initiator, S‐Thiobenzoyl thioglycolic acid as RAFT agent, and Krytox® 257 FSL as stabilizer. It was observed that the polymerization proceeded in a controlled manner. High conversions can be reached in reasonable times. Fairly low polydispersities (around 1.2) are possible if either pressure or temperature are increased, but better results are obtained if the polymerization proceeds at the upper temperature value of 85 °C.