【目的】解决传统相变材料在太阳能存储、余热回收、建筑节能及电子器件热管理等领域应用时普遍存在的“渗漏失效 -热循环不稳定 -储热密度低”问题。【方法】创新性地提出基于结构调控的聚氨酯固 -固相变材料（ PUPCM）分子设计策略：（1）采用六亚甲基二异氰酸酯（ HDI）/尿素与聚乙二醇（ PEG）嵌段共聚，构建线型 PUPCM（L-PUPCM）；（2）利用三苯基甲烷三异氰酸酯（ TTI）与 PEG交联反应，形成三维网络型 PUPCM（C-PUPCM）。通过调控原料配比（线型体系 PEG、HDI和 Urea物质的量比为 1∶2. 2∶0. 2，交联体系 TTI和 PEG物质的量比为 1∶2. 2）及 PEG相对分子质量，系统探究了材料结构与储热性能的构效关系。【结果】 DSC测试表明，线型结构的相变焓达 157. 8 J/g，交联结构相变焓为 125. 3 J/g，均表现出优异相变潜热。傅立叶变换红外光谱仪（FT-IR）分析证实， 2种材料均实现了 PEG相变单元的高效固定，且交联结构展现出更优的尺寸稳定性。【结论】该研究为发展高焓值、高稳定性的固 -固相变材料提供了新的分子设计策略。

［Objective］To address the persistent challenges of leakage failure，thermal cycling instability，and low energy storage density in conventional phase change materials（PCMs）applied to solar energy storage，waste heat recovery，building energy efficiency，and electronics thermal management.［Methods］ This study innovatively proposes a molecular design strategy for polyurethane-based solid-solid PCM（PUPCM） through structural modulation. Specifically，linear main-chain PUPCM（L-PUPCM） was constructed via block copolymerization of hexamethylene diisocyanate（HDI）/urea with poly（ethylene glycol）（PEG），while three-dimensional networked PUPCM（C-PUPCM）was formed through crosslinking reactions between triphenylmethane triisocyanate（TTI） and PEG. Systematic investigations of structure-property relationships were conducted by regulatingfeed ratios［n（PEG）∶n（HDI）∶n（Urea）=1∶2. 2∶0. 2 for linear systems；n（TTI）∶n（PEG）=1∶2.2 for crosslinked systems］ and PEG molecular weights.［Results］ DSC results demonstrated high phase change enthalpies of 157. 8 J/g for linear structures and 125. 3 J/g for crosslinked structures，both exhibiting excellent latent heat. FT-IR analysis confirmed effective immobilization of PEG phase-change units in both materials，with crosslinked structures showing superior dimensional stability.［Conclusion］ This work provides a novel molecular design strategy for developing high-enthalpy， high-stability solid-solid PCMs.