Oxidative polymerizations of methyl methacrylate (MMA) catalyzed by complexes of transition metal halides in high oxidation states were investigated.First

CuBr2/2

2'-bipyridine (bPy)-catalyzed oxidative polymerizations of MMA in the presence of poly(2-(N

N-dimethylamino)ethyl methacrylate) were performed in different solvents.When cyclohexanone was used as a solvent

only poly(methyl methacrylate) (PMMA) was obtained

suggesting redox initiation between CuBr2/bPy and tertiary amines in cyclohexanone is negligible.Second

oxidative polymerizations of MMA catalyzed by different complexes were carried out.Complexes of CuCl2

CuBr2or FeCl3with bPy

N

N

N'

N

N-pentamethyldiethylenetriamine or N

N

N'

N'-tetramethylethylenediamine can catalyze oxidative polymerizations of MMA

and polymerization rates increased with the increase of the catalyst concentration.Molecular weight of PMMA increases with monomer conversions initially and maintains constant later.Last

atom transfer radical polymerization (ATRP) chain extension using PMMA from the oxidative polymerizations at different conversions was performed.The results show the CX functionality of PMMA chains at low conversion was also 100%

and it decreased sharply with conversions.Two different mechanisms were conceived to contribute to the oxidative polymerization of MMA:(1) the complexes form ATRP initiators and catalysts with MMA via monomer addition

and then ATRP proceeds to give rise to PMMA chains with CX terminal groups; (2) the complexes catalyze/initiate conventional free radical polymerizations of MMA.