Synthesis of (meth)acrylamide-based glycomonomers using renewable resources and their polymerization in aqueous systems†
In this work, we present the kinetically-controlled enzymatic synthesis of novel glycosyl-(meth)acrylamide monomers using β-glucosidase. Cellobiose served as the glycosyl donor in the enzyme catalyzed transglycosylation reaction and hydroxyl-alkyl (meth)acrylamides as the glycosyl acceptor. After optimization, we were able to increase the glycomonomer yield up to 68% by changing the glycosyl donor to p-nitrophenyl β-D-glucopyranoside and adding BMIMPF6 as cosolvent. The structure of the glycomonomers was confirmed by 1H NMR, 13C NMR, and mass spectrometry experiments. Aqueous RAFT polymerization of the glycomonomers was successfully performed resulting in glycopolymers with molecular weights up to 30 kg mol−1 and relatively low polydispersity indices (PDI's < 1.30). Free radical polymerization of the glycomonomers was executed as well with the obtained glycopolymers resulting in higher molecular weights and PDI's than the glycopolymers prepared by RAFT polymerization. Thermal properties of the synthesized glycopolymers were investigated via differential scanning calorimetry.