Interpenetrating hydrogel networks based on polyacrylamide and poly(itaconic acid): synthesis and characterization

The synthesis of sequential and simultaneous semi-interpenetrating hydrogel networks (IPNs) based on polyacrylamide (PAAm) and poly(itaconic acid) (PICA) is described. Polyacrylamide was used as a host polymer. Physical properties of IPN hydrogels were determined by IR, swelling, extraction and density measurements. No indication for the formation of hydrogen-bonded complexation was observed by LR spectroscopy. The extraction results showed that the grafting level between the two components of PAAm/PICA in simultaneous semi-IPN is higher than that observed in sequential IPNS. These results confirm that the decrease in swelling ratios with PICA contents is probably due to the entanglement effect. The properties of IPN hydrogels were found to be dependent on the composition and the type of IPN. Both sequential and simultaneous IPNs have quite different morphologies compared to the pure PAAm host hydrogel.