A Sugar Decorated Macromolecular Bottle Brush by Carbohydrate-Initiated Cationic Ring-Opening Polymerization

The capability of a range of protected glucose- (Glc), galactose- (Gal), and fructose- (Fru) based tosylates and triflates to initiate the living cationic ring-opening polymerization of 2-ethyl-2-oxazoline (EtOx) was investigated by detailed kinetic studies utilizing 1 H and 19 F NMR spectroscopy and SEC as well as MALDI and ESI TOF mass spectrometry. The Glc and Gal tosylates and a sterically hindered Fru triflate revealed slow and incomplete initiation, whereas the Glc and Gal triflates resulted in living polymerizations. Well-defined Glc as well as Gal α-end-functionalized PEtOx was obtained after deprotection. Functionalization of the living oxazolinium chain ends with methacrylate anions resulted in a macromonomer that was applied for RAFT polymerization. Deprotection resulted in a comb polymer that is selectively functionalized with Glc at the ends of all side chains (DP backbone = 13, DP side chains = 10, PDI = 1.11).