Interpenetrating polymer network systems based on poly(dimethylaminoethyl methacrylate) and a copolymer containing pendant spiroacetal moieties.

The interpenetrating polymer networks (IPNs) are promising materials due to their unique properties. In this context, in the present study, new IPN structures based on poly(dimethylaminoethyl methacrylate) (PDMAEMA) and poly(itaconic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro[5.5] undecane) (PITAU) were synthesized. The double network was prepared by synthesizing and crosslinking (with N, N'-methylenebis(acrylamide)) PDMAEMA in the presence of a preformed PITAU network. The effect of the two components upon some properties such us: viscoelasticity, thermal stability and swelling behavior of the new prepared gels were deeply investigated. The viscoelastic parameters indicated stronger networks for PDMAEMA/PITAU hydrogels as compared with PDMAEMA. The thermal parameters also indicate that the IPNs are more stable than PDMAEMA. The IPNs present an increased sensitivity to temperature and pH, the equilibrium swelling degree being strongly influenced by them. This behaviour highlights the possibility of controlling the release of therapeutic agents by swelling and deswelling cycles of the IPNs at different pH and temperatures, depending on composition and the application envisaged.