To address the issues of poor thermal stability and thermal conductivity in polyurethane (PU) shell microencapsulated phase change materials (MEPCMs), this study prepared PU/SiO2-MEPCMs using an interfacial polymerization method combined with electrostatic self-assembly technology. First, the PU shell was synthesized via an interfacial polymerization reaction between isophorone diisocyanate (IPDI) and triethanolamine (TEA). Subsequently, the hydrolyzed product of tetraethyl orthosilicate (TEOS), monosilicic acid (Si (OH)4), was adsorbed onto the PU shell surface using electrostatic self-assembly technology and reacted with the –NCO groups to form an SiO2 shell. The effects of the PU/SiO2 composite shell on the surface morphology, chemical structure, compactness, thermal stability, phase transition performance, thermal conductivity, and thermal cycling stability of MEPCMs were investigated. The results showed that the formation of the PU/SiO2 composite shell significantly improved the thermal stability, compactness, thermal conductivity, and cyclic stability of MEPCMs. After continuous treatment at 150°C for 120 min, the leakage rate of the core material decreased from 12.13 % to 3.74 %, and the heat-resistant temperature (T95 %) increased by 30°C. Even after 1000 thermal cycles, MEPCMs still exhibited excellent heat storage performance. Additionally, even under high temperature conditions of 257°C (where pure butyl stearate completely decomposes), the PU/SiO2-MEPCMs still maintained a stable core-shell structure. The introduction of the SiO2 shell greatly enhanced the thermal conductivity of MEPCMs, aligning the phase change temperature more closely with that of the core material and effectively reducing the supercooling phenomenon. Furthermore, the stable energy storage system formed by MEPCMs on the finished fabric surface can endow it with excellent temperature regulation functionality.

中文翻译：

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高热稳定性和导热性PU/SiO2复合壳微胶囊相变材料的制备


针对聚氨酯（PU）壳微胶囊相变材料（MEPCM）热稳定性和导热性差的问题，本研究采用界面聚合方法结合静电自组装技术制备了PU/SiO2-MEPCM。首先，通过异佛尔酮二异氰酸酯（IPDI）和三乙醇胺（TEA）之间的界面聚合反应合成PU壳。随后，利用静电自组装技术将原硅酸四乙酯（TEOS）的水解产物单硅酸（Si（OH）4）吸附到PU壳表面，并与-NCO基团反应形成SiO2壳。研究了PU/SiO2复合壳对MEPCM表面形貌、化学结构、致密性、热稳定性、相变性能、导热系数和热循环稳定性的影响。结果表明，PU/SiO2复合壳的形成显着提高了MEPCM的热稳定性、致密性、导热性和循环稳定性。 150℃连续处理120min后，芯材泄漏率由12.13%下降至3.74%，耐热温度（T95%）提高30℃。即使经过1000次热循环，MEPCM仍然表现出优异的蓄热性能。此外，即使在257℃的高温条件下（纯硬脂酸丁酯完全分解），PU/SiO2-MEPCM仍保持稳定的核壳结构。 SiO2壳层的引入大大增强了MEPCM的导热性，使相变温度与芯材的相变温度更加接近，有效减少了过冷现象。 此外，MEPCM在成品织物表面形成的稳定的能量存储系统可以赋予其优异的温度调节功能。