|227. Muthukrishnan, S.; Zhang, M.; Burkhardt, M.; Drechsler, M.; Mori, H.; Müller, A.H.E.: Molecular Sugar Sticks: Cylindrical Glycopolymer Brushes, Macromolecules 38, 7926 (2005)|
We report the synthesis of glycocylindrical brushes (molecular sugar sticks) with poly(3-O-methacryloyl-α,β-D-glucopyranose), (PMAGlc) side chains, using the grafting from approach via atom transfer radical polymerization (ATRP) of the protected monomer, 3-O-methacryloyl-1,2:5,6-di-O-isopropylidene-D-glucofuranose (MAIGlc). The formation of well-defined brushes with narrow length distribution was confirmed by GPC-MALS and 1H NMR. The initiating efficiency of the initiating sites of the polyinitiator, poly(2-(2-bromoisobutyryloxy)ethyl methacrylate) were determined to be in the range of 0.23 < f < 0.38 by cleaving the side chains from the backbone. The cleaved side chains were analyzed using 1H NMR, GPC/viscosity and GPC-MALS measurements. In spite of the rather low initiating efficiency, the glycocylindrical brushes show the characteristic worm-like structure, as visualized by SFM. The deprotection of the isopropylidene groups of the PMAIGlc side chains resulted in water-soluble glycocylindrical brushes. SFM measurements, cryogenic transmission electron microscopy and dynamic light scattering show a stretched, worm-like structure.