Effect of storage conditions on MMA polymerization via Fe(III)-mediated ATRP without any reducing agent

In a variety of storage conditions, Fe(III)-mediated polymerization of methyl methacrylate (MMA) uses FeX₃ (X=Cl & Br), diphenyl-2-pyridylphosphine (DPPP) ligand and ethyl-2-bromoisobutyrate (EBriB) as an initiator at 80 C in toluene without using any external reducing agents. The FeCl₃ and FeBr₃ containing 980 and 1,890 ppm of water during outside storage for 2 and 4 days, respectively, were successfully used for MMA polymerization through atom transfer radical polymerization (ATRP) without using any reducing agent. Moisture content of the polymerization system increases as the period of outside storage increases. It turned out that most of the polymerizations were under control even after keeping metal salts and their complexes outdoors for 4 days exhibiting a polydispersity less than 1.5. The kinetic plot between ln [M]₀/[M] and time demonstrated linearity during the polymerization. A chain extension study clearly reveals that the moisture contaminated FeX₃ due to outdoor storage, is able to catalyze the ATRP of MMA in the absence of any additive by a living radical mechanism. [Figure not available: see fulltext.]