Complexation phenomena in pH-responsive copolymer networks with pendent saccharides

Sugar-containing copolymer networks of poly(methacrylic acid-co-methacryloxyethyl glucoside) were prepared by free-radical photopolymerization. Incorporation of the MAA in the polymer networks rendered the networks complex forming, in response to the environmental pH change. Using ATR-FTIR spectroscopy, the polymer complexes were investigated in their hydrated state: It was observed that in acidic media hydrogen bonds formed due to the protonation of the carboxylic acid groups of the PMAA while in basic or neutral conditions electrostatic repulsion occurred between the ionized carboxylic acid groups. This complexation affected the macroscopic swelling properties. The effect of copolymer compositions on the network structure was investigated. Both hydrogen-bonding and electrostatic interactions increased with MAA content in the networks.