Poly(ester urethane)s represent a widely investigated class of thermoplastic polymers that exhibit a thermally triggered dual shape memory effect. This behavior is the result of urethane‐rich hard segments that define the permanent shape, while domains formed by the crystallizable polyester segments act as the memory switch. We show here that blending poly(ester urethane)s with a second polyester having a different melting temperature is a straightforward and possibly general approach to create triple‐shape memory polymers, in which two different temporary shapes can be programmed. To demonstrate this, we blended a poly(ester urethane) containing crystallizable poly(1,4‐butylene adipate) segments with poly(butylene succinate) or poly(hexamethylene dodecanoate). The blends microphase separate and the different polyester segments form separate semicrystalline domains, which serve as switching elements that can be activated at different temperatures. The blends retain attractive mechanical properties and the shape memory characteristics are characterized by high fixities (70%–96%) and recovery rates (82%–94%).

中文翻译：

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聚酯（氨基甲酸酯）和聚酯的共混物作为三重形状记忆聚合物的通用设计方法

聚酯（氨基甲酸酯）代表了广泛研究的一类热塑性聚合物，其表现出热触发的双重形状记忆效应。这种行为是由于富含氨基甲酸酯的硬链段定义了永久形状，而可结晶的聚酯链段形成的区域则充当记忆开关。我们在这里表明，将聚（酯氨基甲酸酯）与具有不同熔融温度的第二种聚酯共混是创建三重形状记忆聚合物的一种直接且可能是通用的方法，其中可以编程两个不同的临时形状。为了证明这一点，我们将含有可结晶聚（1,4-丁二酸己二酸酯）链段的聚（酯氨基甲酸酯）与聚（丁二酸丁二酸酯）或聚（六亚甲基十二烷酸酯）共混。共混物微相分离和不同的聚酯链段形成分离的半晶域，它们充当可以在不同温度下活化的开关元件。共混物保留了诱人的机械性能，形状记忆特性的特点是固定性高（70％–96％）和回收率（82％–94％）。