A novel initiating system for controlled radical polymerization of methyl methacrylate

The polymerization of methyl methacrylate (MMA) in bulk is initiated with FeCls · 6H₂O or FeCl₃/PPh₃ at 90°C without the addition any conventional radical initiator to the polymerization system. Although the elucidation of the detailed mechanism of the initiation needs further investigation, it is likely that redox-type reactions are involved in the generation of initiating species. Once the initiating radicals are produced, the polymerization proceeds via reverse atom-transfer radical polymerization (RATRP). It was found that the polymerization is controlled up to a molecular weight of 12 900 at 92% conversion for the system using FeCla · 6H₂O / PPh₃. The chain extension experiment was carried out to confirm the controlled manner of the polymerization system. In both polymerization systems, polydispersity index and the initiator efficiency were found to be <1.4 and 0.6-0.9, respectively.