Reactivity of n-Butyllithium-(CH3)2 NCH2 CH2 OLi System as Catalyst for Copolymerization of Styrene with 1,3-Butadiene

Reactivity of n-butyllithium-(CH3)2 NCH2CH2 OLi system in toluene (System N) and in cyclohexane as catalyst for copolymerization of styrene with 1,3-butadiene was studied. Copolymers obtained with System N ([OLi] /[CLi] = 1.5) were found to contain more styrene units than the feed monomer ratio, which also occurred with the catalyst system n-butyllithium-CH3OCH2CH2OLi (System A). Pale yellow crystalline precipitates were formed in System N. The precipitates were found to have such compositions as C6H5CH2Li·2(CH3)2NCH2CH2OLi and caused an enormous increase in the reactivity of styrene in the copolymerization reactions.