Combining oxyanionic polymerization and click-chemistry: a general strategy for the synthesis of polyether polyol macromonomers

Abstract

We describe a synthetic pathway to tailor-made amphiphilic macromonomers by a combination of anionic ring-opening polymerization and copper-catalyzed azide–alkyne cycloaddition (CuAAC). Linear polyglycerol and poly(glyceryl glycerol) were synthesized in a controlled manner by anionic ring-opening polymerization of ethoxyethyl glycidyl ether or isopropylidene glyceryl glycidyl ether, respectively, with narrow and monomodal molecular weight distributions (Mw/Mn < 1.20) and molecular weights ranging from 850 g mol−1 to 2500 g mol−1. After end-capping with propargyl bromide and removal of the protecting groups, the hydrophilic precursors were quantitatively clicked to a series of hydrophobic azido alkyl methacrylates by copper-catalyzed azide–alkyne cycloaddition obtaining well-defined macromonomers with adjustable amphiphilic properties. Radical polymerization of these amphiphiles afforded graft copolymers with molecular weights up to 470 000 g mol−1 (SEC-MALLS in DMF).