Temperature-Responsive Interpenetrating Polymer Networks Constructed with Poly(acrylic acid) and Poly(N,N-dimethylacrylamide)

Complex formation between PDMAAm as a hydrogen-bonding acceptor and PAAc as a hydrogen-bonding donor, the temperature dependence of the equilibrium swelling for IPN hydrogels composed of PDMAAm and PAAc, and changes in ketoprofen release of these IPN hydrogels were investigated. Interpolymer complexes between PDMAAm and PAAc were very stable at 70°C in aqueous solution. Dissociation temperatures of the complex between poly(DMAAm-co-AAm) and PAAc shifted to higher values with increasing DMAAm content. These IPNs composed of poly(DMAAm-co-AAm) and PAAc showed limited swelling ratios between their swelling transition temperatures and lower swelling ratios above these transition temperatures. Transition temperatures shift to higher values with increasing DMAAm content