Synthesis and characterization of sugar-based methacrylates and their random copolymers by ATRP

Various sugar-based methacrylate monomers have been prepared and randomly copolymerized with methyl methacrylate (MMA) using classical atom transfer radical polymerization (ATRP). Firstly, four different sugar-based methacrylates are synthesized by two-step method: (i) etherification of protected monosaccharides with epichlorohydrin and (ii) following ring-opening reaction of obtained epoxides with methacrylic acid (MAA) in the presence of triethylamine. Next, these monomers are copolymerized with MMA via ATRP at 90 C to obtain corresponding random copolymers. The molecular weights of the copolymers are determined by both GPC (gel permeation chromatography) and 1 H-NMR (nuclear magnetic resonance spectroscopy) analyses and found as 10 600~16 800 and 12 200~18 500 g/mol, respectively. Moreover, the copolymer compositions are also determined by 1 H-NMR analysis using characteristic signals of the monomers and found as about 94.1~97.8%, which are good agreement with feeding ratio. In addition, the glass transition temperatures of copolymers are found as 101.2~102.9 C by changing type and composition of sugar-based methacrylate monomers. Overall, a series of well-defined random copolymers comprising different sugar-based methacrylates and methyl methacrylates were successfully synthesized by classical ATRP method.