Manganese(III) Acetylacetonate Initiated RAFT Polymerizations: An Alternative And Versatile RAFT Initiator

This work describes RAFT polymerization with manganese(III) acetylacetonate(Mn(acac)3) as an initiator. Initiated by Mn(acac)3, RAFT polymerization of poly(vinylacetate) was achieved at80°C mediated by a xanthate, methyl2-(ethoxycarbonothioylthio)propanoate. The polymerization manifested good control at alow concentration of Mn(acac)3(approximately157ppm). The polymer was endowed witha high chain end fidelity (97%), which was comparable or even better in comparison withthe azobisisobutyronitrile-initiated polymerization. The polymerization behavior wasrevealed to comply with the features of a typical RAFT process. SuccessfulMn(acac)3-initiated RAFT polymerization of methyl methacrylate at25°C with a typicaldithioester as a RAFT agent, and styrene at100°C with a dithiocarbamate as a RAFTagent demonstrated that Mn(acac)3was a versatile and superior RAFT initiator.