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

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 (M_w/M_n < 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 470000 g mol^-1 (SEC-MALLS in DMF).