Molecular sugar sticks:: Cylindrical glycopolymer brushes

We report the synthesis of glycocylindrical brushes ("molecular sugar sticks") with poly(3-Omicron-methacryloyl-alpha,beta-D-glucopyranose) (PMAGlc) side chains, using the "grafting from" approach via atom transfer radical polymerization (ATRP) of the protected monomer, 3-Omicron-methacryloyl-1,2:5,6-di-Omicron-isopropylidene-D-glucofuranose (MAIGlc). The formation of well-defined brushes with a narrow length distribution was confirmed by gel permeation chromatography with multiangle light scattering detector (GPC-MALS) and H-1 NMR. The initiating efficiency of the initiating sites of the polyinitiator poly(2-(2-bromoisobutyryloxy)ethyl methacrylate) were determined to be in the range 0.23 < f < 0.38 by cleaving the side chains from the backbone. The cleaved side chains were analyzed using H-1 NMR, GPC/viscosity, and GPC-MALS measurements. Despite the rather low initiating efficiency, the glycocylindrical brushes show the characteristic wormlike structure, as visualized by scanning force microscopy (SFM). The deprotection of the isopropylidene groups of the poly(3-Omicron-methacryloyl-1,2:5,6-di-Omicron-isopropylidene-D-glucofuranose) (PMAIGlc) side chains resulted in water-soluble glycocylindrical brushes. SFM measurements, cryogenic transmission. electron microscopy, and dynamic light scattering show a stretched, wormlike structure.