PREPARATION METHOD OF VINYL AROMATIC HYDROCARBON-CONJUGATED DIENE BLOCK COPOLYMER USING COUPLING REACTION WITH IMPROVED ION STABILITY

摘要

Disclosed is a method for preparing a vinyl aromatic hydrocarbon-conjugated diene block copolymer using a coupling reaction with improved ion stability. The method comprises (a) polymerizing a vinyl aromatic hydrocarbon monomer in a hydrocarbon solvent with an organic lithium compound as a polymerization initiator to prepare a first mix solution comprising a vinyl aromatic hydrocarbon block; and (b) adding a conjugated diene monomer to the first mix solution of step (a) to form a conjugated diene block on an end of the vinyl aromatic hydrocarbon block and to thereby prepare a second mix solution comprising a vinyl aromatic hydrocarbon block-conjugated diene block, wherein the method further comprises (c) adding a Lewis acid to the first mix solution before, during or after polymerization of the vinyl aromatic hydrocarbon monomer of step (a).