HYDROCARBON-SOLUBLE DIFUNCTIONAL AND MULTIFUNCTIONAL ORGANOLITHIUM INITIATORS

Soluble difunctional organolithium initiators were prepared by the addition of oligomeric poly(styryllithium) to stoichiometric amounts of double 1,1-diphenylethylene (DDPE) compounds: bis[4-(1-phenylethenyl)phenyl] ether; 1,4-bis(1-phenylethenyl)benzene, and 4,4'-bis(1-phenylethenyl)-1,1'-biphenyl. The resulting products of this addition reaction were soluble in benzene and were capable of initiating diene polymerization. A reversal was detected at the end of the addition reaction to one of the three DDPE compounds, bis[4-(1-phenylethenyl)phenyl] ether. The diphenyl ether group in bis[4-(1-phenylethenyl)phenyl] ether, which might have reacted with poly(styryllithium) to cause a shift of equilibrium, was suspected to be the cause of the anomaly. The styrene-butadiene-styrene triblock copolymer prepared from these difunctional initiators gave narrow and symmetrical chromatograms by GPC. The tensile strength of the block copolymers, however, was low. A potential route of preparing soluble organolithium initiators with functionality higher than 2 was demonstrated.