The synthesis of oligoalginate derived glycomonomers (AlgiMERs) and their conventional and Reversible Addition Fragmentation chain Transfer (RAFT) polymerizations in aqueous solution were investigated. Firstly, the starting oligoalginates were transformed either into the corresponding glycosylamines or into amino-alditols (via reductive amination). At this stage, optimized amination protocols were identified by carrying out a systematic study on a simpler uronic acid (D-glucuronic acid). Secondly, the obtained amino sugars were reacted with an electrophile bearing a polymerisable vinyl group to yield AlgiMERs. The resulting glycomonomers did not homopolymerize even in high ionic strength and for long reaction times, but their conventional free radical copolymerization with 2-hydroxyethyl methacrylamide (HEMAm) led to high molecular weight glycopolymers (Mw ≈ 1.500.000 Da) containing up to 50 % by mass of oligoalginate. A kinetic study confirmed that the consumption of both monomers followed a first order kinetic and that oligoalginate-derived monomers were incorporated early on in the polymerization process. Based on these results, the investigation was extended to the living radical copolymerization in aqueous solution and well defined gradient glycopolymers were obtained (Mn = 12 000 Da – 90 000 Da; PDI ≤ 1.20). Finally, I could prove that a synthetic polymer carrying oligo(1→4)-α-L-guluronan residues gels in the presence of Ca2+ ions and affords a transparent and stable hydrogel.
