Synthesis and Properties of a Novel Water-Soluble Lactose-Containing Polymer and Its Cross-Linked Hydrogel

A simple and efficient method for the synthesis of lactose-based homopolymers from lactose O-(p-vinylbenzyl)oxime (4) is described. Free radical polymerization of the new oxime monomers proceeded smoothly in an aqueous solution using potassium persulfate (KPS) and N,N,N‘,N‘-tetramethylethylenediamine (TMEDA) as the initiating system and gave water-soluble homopolymers in good yields. These synthetic lactose-based polymers had high molecular weights and narrow polydispersities (Mw/Mn: 1.20−1.35) as determined by size exclusion chromatography, in conjunction with multiangle laser light scattering (SEC−MALLS). The Mark−Houwink equation was obtained as [η] = 2.15 × 10-4Mv0.73. When the monomer was copolymerized with the cross-linking reagent N,N‘-methylenebis(acrylamide) (BisA) (16% mol), hydrogels were formed which swelled as much as 21-fold in deionized water. These gels have potential applications as biocompatible materials.