AGET ATRP of methyl methacrylate via a bimetallic catalyst

In this work, atom transfer radical polymerization with activators generated by electron transfer (AGET ATRP) of methyl methacrylate (MMA) using a novel bimetallic catalyst system based on FeCl3 center dot 6H(2)O/CuCl using tris(3,6-dioxaheptyl) amine (TDA-1) or triphenylphosphine (PPh3) as ligand was carried out in bulk at 90 degrees C for the first time. The kinetics of the polymerizations with a molar ratio of [MMA](0)/[ethyl 2-bromoisobutyrate (EBiB)](0)/[FeCl3 center dot 6H(2)O](0)/[TDA-1 or PPh3](0)/[CuCl](0) = 300 : 1 : 0.5 : 1.5 : 0.1 were studied. At the same time, different reference experiments for the monometallic catalyst system (i.e., MMA/EBiB/FeCl3 center dot 6H(2)O/TDA-1 or PPh3/ascorbic acid, MMA/EBiB/FeCl3 center dot 6H(2)O/TDA-1 or PPh3, MMA/EBiB/FeCl2 center dot 4H(2)O/TDA-1 or PPh3, MMA/EBiB/CuCl/TDA-1 or PPh3) were also investigated. By comparison to these mono-metallic catalyst systems, both the polymerization rate and controllability over molecular weight and molecular weight distribution were enhanced for the bimetallic catalyst system. The nature of "living''/controlled free radical polymerization under bimetallic catalyst system was confirmed by chain extension experiments.