A tough shape memory polymer with triple-shape memory and two-way shape memory properties

In this study, a tough shape memory polymer network based on polydopamine, poly(epsilon-caprolactone) and diisocyanate was synthesized in three steps. Fourier transform infrared spectroscopy was used to confirm the synthesis process. The tensile tests demonstrated the good mechanical properties of the materials with a tensile modulus and tensile strength reaching 362 and 43 MPa, respectively, at room temperature. The thermal properties of the polymer networks were investigated using differential scanning calorimetry and dynamic mechanical analysis. With two broad transition temperatures, the dual-shape memory properties were greatly affected by the deformation temperature, which was investigated in detail. Moreover, the polymers also showed good triple-shape memory and two-way shape memory effects.