Synthesis and characterization of comb-like crosslinking polyurethane based form-stable phase-change materials for thermal energy storage

To prevent the leakage of melting phase-change materials (PCMs), form-stable PCMs (FSPCMs), which usually contain organic PCMs and supporting materials, are prepared via several methods including microencapsulation, physical absorption, grafting PCMs on nanofillers, polymer coating, and so forth. However, the uneven distribution of PCMs in supporting materials affecting the energy storage efficiency is still a severe problem that needs to be considered. Herein, poly(ethylene glycol monomethyl ether)-based trimethylolpropane (Ymer-N120) with long side ethyoxyl segments is the first time used to prepare crosslinked polyurethane (PU) with symmetrical, regular flexible long chains that is designed to improve the distribution of polyethylene glycol (PEGs). The results of Fourier transform infrared spectroscopy, X-ray diffraction, differential scanning calorimetry, accelerated thermal cycling testing, thermogravimetric analysis, and field emission scanning electron microscopy suggested a crosslinked PU containing uniform dispersed PEG crystal was prepared by thermal curing. The FSPCMs can store and release high latent heat (over 110 J/g) with good thermal stability (the initial decomposing-temperature reaches 360 degrees C) without leakage (after 500 times of accelerated thermal cycling testing).

Automated summary

A method using Ymer-N120 to prepare crosslinked polyurethane for improving the distribution of polyethylene glycol in phase-change materials was proposed. Experimental results showed that a crosslinked PU containing uniformly dispersed PEG crystals was prepared by thermal curing, exhibiting high latent heat and good thermal stability.