For the SMPU-OOBAm composites, sample P5 has a bright abundant crystalline texture at 28 °C (Figure 9a) because the crystals of the soft segment of SMPU and OOBA mixed together. When the temperature increases to over 50 °C, part of the bright crystalline texture disappears (see Figure 9b), and the field of vision becomes darker, which suggests the crystal melting of the soft segment of SMPU. When the temperature reaches 76 °C, the composites enter the smectic phase (see Figure 9c). This result is consistent with the DSC curve (see Figure 5b). At 95 °C, the POM image shows the nematic phase, which suggests the phase transition from smectic phase to nematic phase because of the OOBA. When the temperature reaches 106 °C (see Figure 9e), the nematic phase gradually disappears. Compared with pure OOBA, the LC phase transition temperatures shift to lower temperatures in all composites. These results confirm that the aggregation of OOBA mesogen was restrained by the SMPU matrix, which significantly affected the LC phase transitions. In addition, the POM images also demonstrate that some weak crystalline texture is maintained above 180 °C (see Figure 9f), which implies the crystal formation of the hard segment of SMPU. These phenomena are also identified on the DSC curves.