Influence of strain-holding conditions on shape recovery and secondary-shape forming in polyurethane-shape memory polymer
Influence of strain-holding conditions on shape recovery and secondary-shape forming in polyurethane-shape memory polymer
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DOI：
10.1088/0964-1726/15/4/016
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发表时间：
2006-08
影响因子：
4.1
通讯作者：
H. Tobushi;S. Hayashi;Kazumasa Hoshio;N. Miwa
中科院分区：
文献类型：
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作者：
H. Tobushi;S. Hayashi;Kazumasa Hoshio;N. Miwa
在之前对聚氨酯形状记忆聚合物泡沫热机械性能的研究中发现，根据应变保持条件，形状固定性和形状恢复变得不完善，并且出现二次形状形成。影响二次成形的应变保持条件的主要因素是保持温度、保持时间和保持应变。在本研究中，研究了应变保持条件对聚氨酯形状记忆聚合物薄膜的形状恢复和二次形状成型的影响。发现如果保持温度高于玻璃化转变温度，则二次成形显着出现，而如果保持温度低于玻璃化转变温度，则二次成形不出现。如果保持温度高于玻璃化转变温度，则二次成形率随着保持时间的增加而增加。不可恢复应变与保持应变成比例增加。
It was found in previous work on the thermomechanical properties of the polyurethane-shape memory polymer foam that the shape fixity and shape recovery become imperfect and that secondary-shape forming appears, depending on the strain-holding conditions. The main factors of the strain-holding conditions which affect the secondary-shape forming are the holding temperature, holding time and holding strain. In the present study, the influence of the strain-holding conditions on the shape recovery and secondary-shape forming was investigated for the polyurethane-shape memory polymer film. It was found that the secondary-shape forming appears markedly if the holding temperature is higher than the glass transition temperature and does not appear if the holding temperature is lower than the glass transition temperature. The rate of secondary-shape forming increases with an increase in the holding time if the holding temperature is higher than the glass transition temperature. The irrecoverable strain increases in proportion to the holding strain.