A new complex catalytic system CuX/bpy/Al(OR)(3) for atom transfer radicalpolymerization

A new complex catalytic system, consisting of copper (I) halide (CuBr)/2,2' -bipyridine (bpy)/aluminum triisopropoxide [Al(OiPr)(3)], has been successf ully used in the atom transfer radical polymerization (ATRP) of methacrylat es for the first time. The effect of the catalytic system on ATRP has been studied systematically. The mechanism of ATRP promoted by Al(OiPr)(3) has b een elucidated. The study results showed that Al(OiPr)(3), which was used a s a catalytic promoter, decreased polymerization temperature and increased the rate and the controllability of polymerization. With adding proper amou nt of deactivator, CuBr2, both MMA and BMA could be polymerized rapidly at low temperature in a living manner with CuBr/bpy/Al(OiPr)(3) as a ternary c atalytic system. The polymers have the designed degrees of polymerization b y Delta[M]/[I](0) and narrow polydispersity (M-w/M-n = 1.20-1.50). The line ar increase of molecular weight vs. conversion of monomer was observed. The molecular weight distributions (MWD) were narrow and became narrower as co nversion increased. (C) 2000 Elsevier Science B.V. All rights reserved.