Dynamical mechanical properties can also be used to investigate phase transitions by characterizing the changes of the storage modulus. Figure 7 shows the DMA curves of SMPU-OOBAm composites. All of the samples have a large glassy modulus (E’g) below −30 °C, whereas the storage modulus gradually decreases because of the glass transition of the soft segment of SMPU. The first significant storage modulus occurs when the temperature increases to 46 °C, because of the crystal-melting of the soft segment of SMPU. Thereafter, SMPU enters the rubber state. The DMA curves demonstrate that the rubber modulus at 46~60 °C in the SMPU-OOBAm composites tends to be less than those of SMPU. This result again confirms that the OOBA crystals reinforce the crystallinity of the soft segment of SMPU, and act as crystal fillers in the rubber state. The second storage modulus change occurs above 77 °C, particularly in samples with higher OOBA-content. This modulus change should be ascribed to the crystal melting transition of OOBA because it exactly corresponds to the Tm of OOBA. This observation is also notably consistent with the DSC and POM results. Thus, OOBA is another isolated phase that controls the storage modulus. The OOBA isolated phase provides a second reversible phase to the shape fixation and shape recovery. Therefore, SMPU-OOBAm composites may have a triple-shape memory effect.