Multiblock copolymers: PEO stuck in the middle

Anionic polymerization has proven especially useful for the precise construction of multiblock copolymers with controlled compositions and narrow molecular weight distributions. The block copolymer sequences which can be easily prepared are however largely restricted by the relative nucleophilicities of the anionic species involved. This high-light discusses a recent article by Wiesner and co-workers (Macromol. Rapid Commun. 2004, 25, 1889) in which the effective preparation of ABC triblock copolymers, with poly(ethylene oxide) as the central block, through the combination of living anionic polymerization, atom transfer radical polymerization, and polymer modification techniques is described. This method will prove to have a great deal of versatility in allowing the incorporation of PEO blocks in interior positions of block copolymers.