A novel form stable phase change material with comb-like cross-linked polyurethane as supporting skeleton

To improve the homogeneity of phase-change materials (PCMs) composites for thermal energy storage, the poly(ethylene glycol monomethyl ether)-based trimethylolpropane (Ymer-N120) with long side ethyoxyl chains is employed to form comb-like polyurethane which functioned as supporting materials for PCMs. And the results of Fourier transform infrared spectroscopy (FTIR), X-ray diffraction, differential scanning calorimetry, accelerated thermal cycling testing, thermogravimetric analysis and field emission scanning electron microscopy (FESEM) suggested a crosslinked polyurethane embedded with micron grade myristic acid (MA) crystals was prepared during the thermal curing process. The obtained comb-like polyurethane (YP) can provide 3D structure supporting materials for melting MA. And the long side ethyoxyl chain of Ymer-N120 promote the melting MA form micron-sized crystals. The results of thermal reliability testing confirmed the advantages of same methylene groups in side chains and suggested the maximal hold capability of YP crosslinks is about 50 wt% of composites. With the 50 wt% addition of MA, YPM50 can supply high latent heat (over 90 J/g of YPM50) with fine thermal stability (due to its initial decomposing temperature reaches 190 °C) without leakage (after 500 times of accelerated thermal cycling testing). All results indicated this structure supplies an effective solution for the leakage of PCMs, which show a promising application in TES.