Abstract Waterborne polyurethanes (WPUs) with different mass ratios of soft and hard segments were synthesized by toluene diisocyanate, polypropylene glycol (PPG) and ethylene glycol (EG). It was shown that the PPG-based WPU with a mass ratio of soft and hard segments of 3:2 expressed a highest thermal conductivity (∼0.374 W/m·K), but showed a lowest T-peel strength (21.55 N/25 mm). As the mass ratio of soft and hard segments increased to 4:1, the T-peel strength was increased to 136.14 N/25 mm and thermal conductivity was decreased to a lowest value (∼0.306 W/m·K). To gain more understandings a number of analytic were carried out, such as FTIR, TG, DSC, DMA, AFM and XRD. Furthermore, mechanical properties of the PPG-based WPU coatings were tested as well. A possible explanation for the change in properties is due to the degree of phase separation and crystallinity, which was increased with the increasing of hard segment content. As a result, the hard and soft segments formed orderly oriented stacked structures by owing to the increasing of phase separation.

中文翻译：

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水性聚氨酯薄膜中软硬段质量比的变化：导热性能和粘合性能

摘要 以甲苯二异氰酸酯、聚丙二醇（PPG）和乙二醇（EG）为原料合成了不同软硬段质量比的水性聚氨酯（WPU）。结果表明，软硬段质量比为 3:2 的 PPG 基 WPU 表现出最高的热导率 (~0.374 W/m·K)，但表现出最低的 T 剥离强度 (21.55 N/25毫米）。随着软硬段的质量比增加到 4:1，T 剥离强度增加到 136.14 N/25 mm，热导率降低到最低值（~0.306 W/m·K）。为了获得更多的理解，进行了许多分析，如 FTIR、TG、DSC、DMA、AFM 和 XRD。此外，还测试了基于 PPG 的 WPU 涂层的机械性能。性能变化的一个可能解释是相分离和结晶度的程度，随着硬链段含量的增加而增加。结果，由于相分离的增加，硬段和软段形成有序取向的堆叠结构。