Thermomechanical characterization of thermoset urethane shape-memory polymer foams

The shape‐memory polymer performance of urethane foams compressed under a variety of conditions was characterized. The foams were water‐blown thermosets with a closed‐cell structure and ranged in density from about 0.25 to 0.75 g/cm3. Compressive deformations were carried out over a range of strain levels, temperatures, and lateral constraints. Recovery stresses measured between fixed platens were as high as 4 MPa. Recovery strains, measured against loads up to 0.13 MPa, demonstrated the effects of various parameters. The results suggest that compression near the foam glass‐transition temperature provided optimal performance. Foams with densities of about 0.5 g/cc and compressed 50% provided a useful balance (time, strain, and load) in the recovery performance. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010