Hyperbranched Waterborne Polyurethane Solid–Solid Phase Change Material for Thermal Energy Storage in Thermal Management Fabric

Hyperbranched waterborne polyurethane solid–solid phase change material was prepared by A 2  + B 3 method in water. Hyperbranched polyurethane solid–solid phase change material (HBPUPCM) was synthesized through reaction of isocyanate terminated prepolymer (A 2 ) with trimethylolpropane (B 3 ). Fourier transform infrared spectroscopy and 1 H nuclear magnetic resonance were used to confirm the prepared HBPUPCM. Differential scanning calorimetry showed that the maximum latent heat of HBPUPCM was Δ H m of 161.57 J/g and Δ H c of 153.44 J/g. The thermal storage ability was stable even after 500 consecutive heating/cooling cycles. The as-prepared HBPUPCM had excellent thermal stability as was shown by thermogravimetric analyzer. In addition, X-ray diffraction and polarized optical microscopy showed that HBPUPCM had crystalline structure. Meanwhile, when the poly(ethylene glycol) content was 80 wt%, the cotton fabric finished with HBPUPCM had a lower heating and cooling rate, higher phase change enthalpy and better temperature regulation performance in comparison with the unfinished cotton fabric. The HBPUPCM may be highly feasible and promising in the field of intelligent thermoregulation fabric industry.