PMMA-Grafted Dextran Glycopolymers by Atom Transfer Radical Polymerization

The four-step synthesis of amphiphilic glycopolymers associating dextran as backbone and poly(methyl methacrylate) (PMMA) as grafts is reported, using the H grafting from strategy. In the first step, the dextran OH functions were partially acetylated. The second step consisted in linking initiator groups by reaction of 2-bromoisobutyryl bromide ((BBB)-B-i) with the unprotected OH functions. Third, the atom transfer radical polymerization (ATRP) of methyl methacrylate was carried out in DMSO from the resulting dextran derivative used as a macroinitiator. Finally, the cleavage of the acetate groups led to the expected glycopolymers. Careful attention was given both to the copolymer structure and the control of polymerization. PMMA grafts were analyzed by SEC-MALLS after their deliberate cleavage from the backbone to evidence a controlled polymerization. Moreover, the mildness of the final deprotection conditions was proved to ensure acetate cleavage without either degrading dextran backbone and PMMA grafts or cleaving grafts from dextran backbone. (C) 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 7606-7620, 2008