Abstract: This paper reports the kinetic study of butadiene polymerization in toluene with n-butyl lithium and potassium butoxide as catalyst and with or without the addition of polar modifiers. It is found that,when K/Li=0,at 0℃, the reaction order of initiator concentration with respect to polymerization rate was 1; apparent rate constant k_ap of polymerization was independent of the initiator concentration. When K/Li=0.5 and 1.1, A/Li=0, k'=2/100, k_ap differed significantly, but the apparent energy of activation E_ap in both cases gave the same value:45.2kJ/mol. When K/Li<1.0, the polymerization rate increased with increase of K/Li; when K/Li>1.0, the polymerization rate became constant. Addition of polar modifiers greatly increased the rate of polymerization.

Key words: Anion polymerization, Butadiene, Polymerization kinetics, Toluene, Lithium compound, Potassium compound