The influence of heat treatment was also investigated in this study. In Figure 5d, the effect of OOBA in the composites on the thermal properties during the heat treatment was investigated with DSC by heating sample P3 to 100, 120, 140, 160, and 180 °C. When P3 was thermally treated at 120 °C and 140 °C, the cold crystallization peak of the soft phase of SMPU was detected at −11 °C. However, the peak disappears after the thermal treatment at 100 °C, 160 °C, and 180 °C. A possible reason is that the movement of the polymer chains is frozen at low temperature (<100 °C), and the composites cannot form cold crystallization; the higher treatment temperature (≥160 °C) can promote the movement of the polymer chains and cause a complete crystallization of the soft segments when they cool to a low temperature. Thus, there is no cold crystallization in the second heating process. In addition, Figure 5d demonstrates that the crystallization temperatures of both the soft and hard phases of SMPU shift to higher temperatures when the thermal treatment temperature increases. This result also demonstrates that the heat treatment can promote the crystallizability of the soft and hard segments of SMPU. However, the heat treatment results show that the crystal melting transition of OOBA is maintained at 74 °C in all composites. Thus, OOBA can aggregate into an isolated phase and retain its intrinsic LC properties in the SMPU-OOBAm composites.