“Living”radical polymerization of methyl methacrylate was investigated using a new reaction system

ethyl 2-bromoisabutyrate／CuBr／[mim][HCOO]／MMA

in which[mim][HCOO]ionic liquid was a good solvent to CuBr．Polymerization of methyl methaerylate was carried out in[mim][HCOO] in the absence of any organic ligands. The polymerization mechanism belongs to an ATRP process．The polymerization was closely controUed and was a fast reaction when compared to pdymerizafion in non—polar solvents in[mim] [HCOO]at 50℃．The polymers weIe easily separated from the catalyst．Analysis of the PMMA for residual copper by atomic absorption spectrophotometer．shows a copper contentof 3．80×10-3％(1％is expected

if no copperis removed)．