Shape‐Memory Hydrogels with Switching Segments Based on Oligo(<i>ω</i>‐pentadecalactone)

Abstract

Abstract We investigated whether dual‐shape hydrogels based on crosslinked N ‐vinyl‐2‐pyrrolidone can be created, in which oligo( ω ‐pentadecalactone) ( $\overline {M} _{{\rm n}} $ = 2900 g · mol −1 , T m = 89 °C) chain segments contribute to the switching domains. In the obtained hydrogels, the volumetric degree of swelling decreased from 480 to 190% while the E ‐moduli increased from 0.10 to 0.34 MPa with increasing OPDL content. Furthermore, the equilibrium swollen hydrogels displayed good shape‐memory properties with strain fixity ratios above 95% and strain recovery rates above 92%. These shape‐memory hydrogels, whose degree of swelling was almost independent of the temperature, might be interesting candidates for various applications such as stimuli‐sensitive switches or valves. magnified image