Atom-Economical, One-Pot, Self-Initiated Photopolymerization of Lactose Methacrylate for Biobased Hydrogels

An excess of lactose and lactose-rich milk permeate is produced by the dairy industry. The use of these waste products has been investigated for the preparation of sugar-based hydrogels. An environmentally friendly, atom-economical reaction conducted in water with minimal waste was successfully applied in the synthesis of lactose methacrylate. Lactose methacrylate was copolymerized with the methacrylic acid generated as a byproduct of the initial synthesis using photoinduced polymerization to yield hydrogels. The photopolymerization was facilitated by low-intensity UV light (365 nm) without the need for an exogenous photoinitiator. Hydrogels with varied water uptake, rheological, and mechanical properties could be prepared by the use of different methacrylic anhydride loadings in the synthesis of lactose methacrylate.