Aqueous Catalyst-Free Derivatization of Polysaccharides with Epoxides at Neutral pH

High Resolution Image Download MS PowerPoint Slide We report a simple revisited route to derivatize polysaccharides with molecular epoxides or epoxide-functionalized macromolecules in water at neutral pH, without a catalyst. Exploiting model reactions on monosaccharide derivatives, we show that the catalyst-free grafting of epoxides is feasible when performed on carboxylated polysaccharides. Using alginate and glycidyl methacrylate, a degree of substitution up to 0.31 can be achieved within 1 day. Thanks to the mild conditions of derivatization (moderate temperatures, neutral pH, no catalyst), this environmentally friendly strategy enables efficient synthesis of advanced polysaccharide-based architectures with chemically sensitive moieties. In line with this, we successfully obtained water-soluble alginate- g -poly(acrylamide- co -glycidyl methacrylate) hybrids, which are highly sought after for water treatment applications, by grafting short hydrophilic epoxide- and xanthate-functionalized poly(AM- co -GMA) copolymers, followed by reversible addition–fragmentation chain transfer chain extension.