Synthesis of AB(BA), ABA and BAB block copolymers of tert‐butyl methacrylate (A) and ethylene oxide (B)

Well‐defined AB(BA), ABA, and BAB block copolymers of tert‐butyl methacrylate (tBMA) (A) and ethylene oxide (EO) (B) have been prepared by sequential living anionic polymerization of the two comonomers, irrespective of their addition order. Diphenyl methyl potassium and naphthalene potassium have been successfully used as mono‐ and difunctional initiators, respectively. In all cases, molecular weight and composition of the block copolymers can be predicted on the basis of the monomer over initiator molar ratio, and the molecular weight distribution is relatively narrow. Size exclusion chromatography, selective extractions of homopolymers, and 1H‐ and 13C‐NMR spectroscopy support that block copolymerization proceeds without homopolymer formation nor side reactions, e.g., transesterification reactions. The PtBMA blocks have been quantitatively hydrolyzed into polyacid ones with formation of polyacid‐b‐polyether block copolymers as supported by titration, 1H‐NMR, and IR analysis. © 1992 John Wiley & Sons, Inc. Copyright © 1992 John Wiley & Sons, Inc.