Abstract Water-actuated shape memory polymers (SMPs) have great potential applications in many fields. Although many strategies have been developed to endow polymers with water-active shape memory effect (SME), so far it is still challenging to prepare the water-actuated SMPs with a highly sensitive SME in a method as facile as possible. In this work, poly(vinyl alcohol) (PVA) was incorporated into poly(ethylene vinyl acetate) (EVA) through the simple solution compounding processing. The blends exhibited good interfacial interaction on one hand. On the other hand, PVA exhibited excellent reinforcement effect, leading to the great enhancement of modulus and strength. Further results showed that the samples had excellent water uptake and dehydration abilities, and the presence of water resulted in the dramatic decrease of modulus and large increase of tensile ductility, which endowed the materials with great potential to realize complicated deformation at gentle force. The water-active SME was evaluated through cycling measurements, i.e. wetting-stretching-drying processes. The results showed that the water-active SME of the blends was greatly dependent upon the blend compositions. After several cycling measurements, the water-active SME of samples became stable. Specifically, for the sample containing 35 wt% PVA, the shape fixity and shape recovery ratios were increased up to 98.7% and 99.5%, respectively. The mechanisms for the excellent water-active SME were then discussed.

中文翻译：

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通过添加亲水性聚（乙烯醇）实现水驱动形状记忆和机械适应性聚（乙烯醋酸乙烯酯）

摘要 水驱动形状记忆聚合物（SMPs）在许多领域具有巨大的应用潜力。尽管已经开发了许多策略来赋予聚合物水活性形状记忆效应 (SME)，但到目前为止，以尽可能简便的方法制备具有高度敏感 SME 的水驱动 SMP 仍然具有挑战性。在这项工作中，通过简单的溶液复合加工将聚（乙烯醇）（PVA）掺入聚（乙烯醋酸乙烯酯）（EVA）中。一方面，共混物表现出良好的界面相互作用。另一方面，PVA表现出优异的增强效果，导致模量和强度的大幅提高。进一步的结果表明，样品具有优异的吸水和脱水能力，水的存在导致模量急剧下降，拉伸延展性大幅增加，这赋予了材料在温和力下实现复杂变形的巨大潜力。水活性 SME 通过循环测量进行评估，即润湿-拉伸-干燥过程。结果表明共混物的水活性 SME 在很大程度上取决于共混物组成。经过多次循环测量，样品的水活性 SME 变得稳定。具体而言，对于含有 35 wt% PVA 的样品，形状固定率和形状恢复率分别增加到 98.7% 和 99.5%。然后讨论了优异的水活性 SME 的机制。水活性 SME 通过循环测量进行评估，即润湿-拉伸-干燥过程。结果表明共混物的水活性 SME 在很大程度上取决于共混物组成。经过多次循环测量后，样品的水活性 SME 变得稳定。具体而言，对于含有 35 wt% PVA 的样品，形状固定率和形状恢复率分别增加到 98.7% 和 99.5%。然后讨论了优秀的水活性 SME 的机制。水活性 SME 通过循环测量进行评估，即润湿-拉伸-干燥过程。结果表明共混物的水活性 SME 在很大程度上取决于共混物组成。经过多次循环测量后，样品的水活性 SME 变得稳定。具体而言，对于含有 35 wt% PVA 的样品，形状固定率和形状恢复率分别增加到 98.7% 和 99.5%。然后讨论了优秀的水活性 SME 的机制。对于含有 35 wt% PVA 的样品，形状固定率和形状恢复率分别增加到 98.7% 和 99.5%。然后讨论了优异的水活性 SME 的机制。对于含有 35 wt% PVA 的样品，形状固定率和形状恢复率分别增加到 98.7% 和 99.5%。然后讨论了优秀的水活性 SME 的机制。