Effects of ester chain length and temperature on the catalytic chain transfer polymerization of methacrylates

The catalytic chain transfer polymerizations of methyl, ethyl, and butyl methacrylates were studied over the temperature range 40-70°C with cobaloxime boron fluoride (COBF) and its tetraphenyl derivative (COPhBF). It was found that for both catalytic chain transfer agents the chain transfer constant decreases in going from methyl to butyl methacrylate, and that there is no significant temperature effect on the observed chain transfer constants. The results are consistent with a diffusion-controlled rate coefficient for the chain transfer reaction.