Investigation of a hyperbranched polyurethane as a solid-state phase change material

As phase change material (PCM), doped hyperbranched polyurethane (D-HBPU) was synthesized by PEG6000 via two steps: at first take tetrafunctional pentaerythritol as soft segment, and then use liquefaction-modified isocyanate, and chain extender as hard segment. This material’s molecular structure, phase change behaviors, thermal-resistant property, and crystalline morphology had been investigated by Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analyses, wide-angle X-ray diffraction (WAXD), and polarization optical microscopy (POM). Results showed that D-HBPU was a typical solid-state PCM with better heat storage property and thermal resistance when compared with hyperbranched polyurethane. The transition enthalpy and the main decomposition temperature of D-HBPU were 125.0 J/g and 437 °C, respectively. From WAXD and POM, the results suggested that D-HBPU has good crystallization.