Polyethylene glycol (PEG)-based solid–solid phase change materials (SSPCMs) were first synthesized using PEG and hexamethylene diisocyanate trimer (HDIT) via one-step and solvent-free approach. When HDIT content is 5 wt %, the obtained SSPCM has no leakage at 80 °C which is higher than the melting temperature of PEG, the phase change temperatures, maximum latent heat and relative enthalpy efficiency of the obtained SSPCM are 65 °C, 136.8 J/g and 87.1%, respectively. After 200 thermal cycles, the latent heat remains nearly constant. It proves that the fabricated SSPCMs has good thermal reliability and reusability. At the same time, the SSPCMs own excellent light-thermal conversion performance and good thermal stability in a broad temperature range of applications. All the above results show that the obtained SSPCMs own great potential as direct solar light absorber for solar thermal energy storage.

中文翻译：

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一步法合成无溶剂的基于聚乙二醇的聚氨酯作为固-固相变材料，用于太阳能热能存储

基于聚乙二醇（PEG）的固-固相变材料（SSPCM）首先使用PEG和六亚甲基二异氰酸酯三聚体（HDIT）通过一步和无溶剂方法合成。当HDIT含量为5 wt％时，所获得的SSPCM在80°C时没有泄漏，高于PEG的熔融温度，相变温度，最大潜热和相对焓效率为65°C，136.8。 J / g和87.1％。经过200个热循环后，潜热几乎保持恒定。证明了所制造的SSPCM具有良好的热可靠性和可重复使用性。同时，SSPCM在广泛的应用温度范围内具有出色的光热转换性能和良好的热稳定性。