Synthesis of polyacrylamide/polyurethane hydrogels by latex IPN and AB crosslinked polymers

Interpenetrating polymer network (IPN) and AB crosslinked polymer (ABCP) hydrogels composed of polyacrylamide (PAAm) and polyurethane (PU) have been synthesized as function of degree of polymerization of PU prepolymer, crosslink density of PAAm domain, and gel composition. Both PAAm/PU IPN and ABCP gels gave synergistic effects in terms of density showing positive deviation from the linear additivity. As a result of this, the strength of swollen gel increased over approximately two times with a small addition of flexible PU (10–20%) to the rigid PAAm.