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

A new complex catalytic system, consisting of copper (I) halide (CuBr)/2,2'-bipyridine (bpy)/aluminum triisopropoxide [Al(OiPr)(3)], has been successfully used in the atom transfer radical polymerization (ATRP) of methacrylates 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 been elucidated. The study results showed that Al(OiPr)(3), which was used as a catalytic promoter, decreased polymerization temperature and increased the rate and the controllability of polymerization. With adding proper amount 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 catalytic system. The polymers have the designed degrees of polymerization by Delta[M]/[I](0) and narrow polydispersity (M-w/M-n = 1.20-1.50). The linear increase of molecular weight vs. conversion of monomer was observed. The molecular weight distributions (MWD) were narrow and became narrower as conversion increased. (C) 2000 Elsevier Science B.V. All rights reserved.