Tunable Shape Memory Performances via Multilayer Assembly of Thermoplastic Polyurethane and Polycaprolactone.
Tunable Shape Memory Performances via Multilayer Assembly of Thermoplastic Polyurethane and Polycaprolactone.
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DOI：
10.1021/acsami.5b10246
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发表时间：
2016-01
影响因子：
9.5
通讯作者：
Yu Zheng;R. Dong;Jiabin Shen;Shaoyun Guo
中科院分区：
文献类型：
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作者：
Yu Zheng;R. Dong;Jiabin Shen;Shaoyun Guo
采用增层挤出法制备了热塑性聚氨酯（TPU）和聚己内酯（PCL）交替层的形状记忆材料。多层膜结构是一种特殊的共连续形态，具有稳定的连续层间距，可以通过改变层数来控制。与传统的聚合物共混物相比，具有相同组成的多层组装系统具有更高的形状固定和恢复率，可以通过增加层数进一步提高。通过粘弹性模型分析，弹性TPU层中保留的变形能将通过界面剪切效应被相邻的PCL层平衡，使得多层结构中的每个组分能够对形状固定和恢复阶段做出最大贡献。此外，还分别考察了TPU层的硬度和PCL层的形态对复合材料性能的影响。结果表明，选择低硬度的TPU或用具有共连续形态的TPU/PCL共混物代替纯PCL层有利于获得优异的形状记忆性能。
Shape memory materials containing alternating layers of thermoplastic polyurethane (TPU) and polycaprolactone (PCL) were fabricated through layer-multiplying extrusion. As a type of special co-continuous morphology, the multilayer structure had stable and well-defined continuous layer spaces and could be controlled by changing the number of layers. Compared with conventional polymer blends, the multilayer-assembled system with the same compositions had higher shape-fixing and -recovery ratios that could be further improved by increasing the number of layers. By analyzing from a viscoelastic model, the deformation energy preserved in elastic TPU layers would be balanced by adjacent PCL layers through interfacial shearing effect so that each component in the multilayer structure was capable of endowing the maximum contribution to both of the shape-fixing and -recovery stages. Besides, the influence of the hardness of TPU layers and the morphology of PCL layers were respectively concerned as well. Results revealed that choosing low-hardness TPU or replacing neat PCL layers by TPU/PCL blend with co-continuous morphology were beneficial to achieving outstanding shape memory performances.