Development of Polymeric Phase Change Materials On the basis of Diels−Alder Chemistry

Diels−Alder (DA) chemistry is increasing popular due to its simplicity and efficiency; however, one concept that has yet to be thoroughly explored is incorporation of DA linkages within materials for the development of polymeric phase change materials. It is well established that the retro-DA reaction results in a large endotherm, which could be a potential energy sink for phase change materials. Hydroxyl-terminated polybutadiene (HTPB) was selected as a prepolymer and modified with different DA linkages. Cured materials were prepared upon addition of diisocyanates and their physical properties of the cured elastomers were investigated using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and rheological testing. The resulting thermally responsive HTPB (TR-HTPB) exhibited the ability to absorb energy and flow at elevated temperatures. Furthermore, they displayed unusual responses to repeated thermal cycling, including changes in thermal absorption and rheological characteristics.