Abstract Vacuum adsorption was conducted to fabricate bio-based polyethylene glycol (PEG)/wood flour (WF) composites as novel shape-stable phase change materials (SSPCMs). The structure–property relationships and comprehensive performance of PEG/WF phase change materials (PCMs) prepared with different average molecular weights of PEG and different length-to-diameter ratios of WF were investigated through various characterization techniques. The relationship between the average molecular weight and mass content of PEG with the properties and structure of the prepared PEG/WF PCMs was evaluated. Leakage test results showed that WF with a high length-to-diameter ratio (HWF) exhibited much higher adsorption capacity for PEG than that of WF with a low length-to-diameter ratio (LWF). The maximum adsorption content of PEG was found to be 70 wt% in those PEG/HWF PCMs and both proceeded with excellent shape stability without leakage when the average molecular weight of PEG was more than 4000. The maximum content of PEG1000 in novel PEG/HWF PCMs without any leakage above the melting point of PEG was 75 wt%. Fourier transform infrared (FT-IR) spectroscopy results indicated that physical interactions occurred between WF and PEG, but chemical reactions did not take place. X-ray diffraction (XRD) analysis demonstrated that the crystallization of PEG in SSPCMs decreased. Differential scanning calorimetry (DSC) analysis demonstrated that the phase transition temperature did not depend on the content and length-to-diameter ratio of the WF. Simultaneously, the highest melting latent heat of the prepared PEG/HWF SSPCM was 108.6 J/g, and its enthalpy efficiency reached more than 75.05%. Thermal cycling test and TGA analysis results demonstrated that PEG/WF SSPCMs had good thermal reliability and chemical stability and showed potential for applications in solar thermal energy storage and biomass energy.

中文翻译：

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无溶剂制备生物基聚乙二醇/木粉复合材料作为太阳能热能储存的新型形状稳定相变材料

摘要 真空吸附制备生物基聚乙二醇（PEG）/木粉（WF）复合材料作为新型形状稳定相变材料（SSPCMs）。通过各种表征技术研究了用不同平均分子量的 PEG 和不同长径比制备的 PEG/WF 相变材料 (PCM) 的结构-性质关系和综合性能。评价了PEG的平均分子量和质量含量与制备的PEG/WF PCMs的性质和结构之间的关系。泄漏测试结果表明，高长径比 (HWF) 的 WF 对 PEG 的吸附能力远高于低长径比 (LWF) 的 WF。当PEG的平均分子量超过4000时，PEG/HWF PCMs中PEG的最大吸附量为70wt％，并且均具有优异的形状稳定性而不会泄漏。 新型PEG/HWF中PEG1000的最大含量在 PEG 熔点以上没有任何泄漏的 PCM 为 75 重量％。傅里叶变换红外 (FT-IR) 光谱结果表明 WF 和 PEG 之间发生了物理相互作用，但没有发生化学反应。X 射线衍射 (XRD) 分析表明 SSPCM 中 PEG 的结晶减少。差示扫描量热法 (DSC) 分析表明，相变温度与 WF 的含量和长径比无关。同时，制备的 PEG/HWF SSPCM 的最高熔融潜热为 108.6 J/g，其焓效率达到75.05%以上。热循环测试和 TGA 分析结果表明 PEG/WF SSPCMs 具有良好的热可靠性和化学稳定性，在太阳能热能存储和生物质能方面显示出应用潜力。