| abstract |
Process for the preparation of an efficient industrial organolithium diinitiator, comprising the reaction of two equivalents mono-organolithium initiator with one equivalent of 1,3-diisopropenyl benzene at a temperature in the range of from -20 to 60 °C, in an apolar hydrocarbon solvent, and in the presence of a monofunctional tertiary amine in a molar ratio relative to mono-organolithium initiator from 0.5 to 2, followed by addition to the reaction mixture of a small amount of conjugated diene monomer, at a temperature in the range of from 0 to 30 °C, to form a solution of an α,ω-dilithio poly(conjugated diene), having an apparent molecular weight in the range of from 1000 to 3000; reaction product solution comprising said stable α,ω-dilithio initiator and process for the preparation of symmetrical block copolymers using said α,ω-dilithio initiator. |