RADIAL MULTI-BLOCK COPOLYMERS

摘要

A process for making a radial multi-block copolymer, comprising: (a) anionically polymerizing styrene monomer A1, at least one monovinylarene monomer A2 other than styrene and at least one conjugated diene monomer B using a lithium-based initiator to form block copolymer chains; (b) adding a metal alkyl compound other than the lithium-based initiator after initiating anionic polymerization in step (a), wherein the molar ratio of the metal alkyl compound to lithium is greater than about 2.0; and (c) adding a coupling agent having more than two functional groups to form the radial multi-block copolymer, wherein the radial multi-block copolymer comprises a residue Z derived from the coupling agent and block copolymer chains from step (b) coupled to the residue Z.