Abstract: The chain transfer of butadiene polymerization was studied with n-butyl lithium and potassium butoxide as catalyst, toluene as solvent and chain transfer agent. The chain transfer constants to toluene with different counterions were found to be:C_s(Li)=0.11x10^-3, C_s(Na)=0.40x10^-3, C_s(K)=1.43x10^-3, (K/Li=1.1), C_s(K))=1.26x10^-3K/Li=0.5) respectively. The propagation rate constant increased 1.7 times for every 10℃ increase in temperature, and the chain transfer rate constant increased 2.1 times. The apparent activation energy of chain transfer was 62.8 kJ/mol. When increeasing K/Li from 0 to 0.5, C_s increased about 10 times, but when K/Li increased from 0.5 to 1.1, C_s changed scantly. Probably there existed certain chain transfer to monomer in this system.

Key words: Butadiene Anionic initiation polymerization Toluene Chain transfer