Solvent-free synthesis of PEG modified polyurethane solid-solid phase change materials with different Mw for thermal energy storage

The different molecular weights of polyurethane (PU), using as solid-solid phase change materials, were synthesized by different molar ratios of polyethylene glycol (PEG, Mn = 8000), 4,4'-methylenebis (cyclohexyl isocyanate) (H12MDI), and Emulsogen TS200 (tristyrylphenol polyglycol ether), through solvent-free bulk polymerization method. Differential scanning calorimetry (DSC), wide-angle X-ray diffraction (WAXD), and polarization optical microscopy (POM) were applied to examine the characteristics of phase transition and crystalline morphology. According to the results of examination, both latent heat and crystalline structure were affected by the molecular weight. The enthalpies of fusion and crystallization reached up to 129.59 and 105.45 J/g, respectively, suggesting a promising future for this phase change material to be applied in thermal energy storage.

Automated summary

Polyurethane with different molecular weights, as solid-solid phase change materials, were synthesized by solvent-free bulk polymerization method. The molecular weight was found to affect both latent heat and crystalline structure, showing promising application potential in thermal energy storage.