A new amino-terminated oligomer with amide units was synthesized by polycondensation reaction of diethyl oxalate and amino-terminated polypropylene oxide of 400 g/mol, which was used to prepare novel polyurethane elastomer containing amide units in soft segments and urea units in hard segments (PU-A2000). To explore the effects of amide and urea units on the physical properties and microstructures of polyurethane elastomers (PUEs), amino-terminated polypropylene oxide and polypropylene glycol based polyurethane elastomers (PU-D2000 and PU-PPG2000 respectively) were prepared and investigated. Characterization results exhibited that the urea units in the hard segments could distinctly enhance the mechanical properties of PUEs at elevated temperatures. Especially, the tear strength retention rate at 120 °C of PU-D2000 was 18.8% higher than that of PU-PPG2000 with only urethane based hard segments. More significantly, the tear and tensile strength of PU-D2000 and PU-A2000 with urea units in hard segments were invariable for nearly 3 h at 100 °C in comparison with the gradual decline in tear strength of PU-PPG2000. The amide units in the soft segments effectively weakened the intermolecular interaction between soft segments and hard segments and promoted the microphase separation, which further induced remarkably improved mechanical properties at high temperatures of PUEs, specifically, the tear strength retention rate at 120 °C of PU-A2000 was 17% higher than that of PU-D2000. On the whole, the tear strength retention rate of PU-A2000 at 120 °C was 35.6% higher than that of conventional PU-PPG2000, indicating that it is a promising strategy to enhance the mechanical properties at high temperatures of PUEs by incorporating urea units into the hard segments and amide units into the soft segments.

草酸二乙酯与端氨基聚环氧丙烷以400 g/mol缩聚反应合成了一种新型的带酰胺单元的端氨基低聚物，用于制备软链段含酰胺单元、硬链段含尿素单元的新型聚氨酯弹性体。 PU-A2000）。为了探索酰胺和脲单元对聚氨酯弹性体 (PUE) 物理性能和微观结构的影响，制备并研究了端氨基聚环氧丙烷和聚丙二醇基聚氨酯弹性体（分别为 PU-D2000 和 PU-PPG2000）。表征结果表明，硬段中的尿素单元可以明显提高 PUE 在高温下的机械性能。尤其是PU-D2000在120℃的撕裂强度保持率为18。比仅含氨基甲酸酯基硬链段的 PU-PPG2000 高 8%。更重要的是，与 PU-PPG2000 的撕裂强度逐渐下降相比，PU-D2000 和 PU-A2000 的撕裂强度和拉伸强度在 100°C 下在近 3 小时内保持不变。软链段中的酰胺单元有效削弱了软链段和硬链段之间的分子间相互作用，促进了微相分离，进一步显着提高了PUE的高温力学性能，特别是PU在120°C下的撕裂强度保持率-A2000 比 PU-D2000 高 17%。整体来看，PU-A2000在120℃的撕裂强度保持率比传统PU-PPG2000高35.6%，