Novel interpenetrating networks with shape‐memory properties

Novel polyesterurethane/poly(ethylene glycol) dimethacrylate (PEGDMA) interpenetrating networks (IPNs) with good shape‐memory properties were synthesized using solvent casting method. The star‐shaped oligo(rac‐lactide)‐co‐glycolide] was coupled with isophorone diisocyanate to form a polyesterurethane network (PULG), and PEGDMA was photopolymerized to form another polyetheracrylate network. IPNs were transparent and gel content exceeded 92%. The values of strain fixity rate and strain recovery rate were above 93%. PULG and PEGDMA networks in IPNs were amorphous and did not show any characteristic diffraction peaks in X‐ray diffraction spectra. Only one glass transition temperature (T_g) of the IPNs between T_g of PEGDMA and PULG was observed, which was proportional to PEGDMA content. PULG and PEGDMA networks were miscible when PEGDMA content was below 50 wt %. The hydrophilicity, transition temperatures, and mechanical properties of IPNs could be conveniently adjusted through variation of network compositions to match the promising potential clinical or medical applications. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 768–775, 2007