Modified sodium acetate trihydrate/expanded perlite composite phase change material encapsulated by epoxy resin for radiant floor heating

In this study, sodium acetate trihydrate was modified with urea, ethylene glycol, and disodium hydrogen phosphate dodecahydrate. The modified phase change material was impregnated into expanded perlite to obtain a composite phase change material, which was encapsulated with epoxy resin as the coating to obtain a coated composite phase change material with a phase change temperature of 46.4 °C, a latent heat of phase change of 132.7 J/g, and a low supercooling temperature of 0.6 °C. Leak tests and thermal cycle stability showed that the coating could effectively slow down the escape rate of the liquid phase and solve the macroscopic leakage problem. Moreover, the decrease in latent heat was only 1.8 % after 100 cycles, demonstrating excellent thermal cycle stability. The morphology and elemental distribution of the modified phase change materials and coatings were studied. In addition, laboratory insulation simulation tests were conducted, and the coated composite phase change material panels showed a significant delay in temperature reduction, while the insulation box showed longer lasting thermal performance. The excellent properties of the material find their application in radiant floor heating systems and play a key role in the expansion of coated phase change materials.