Polyurethane has emerged as an excellent potential candidate for shape memory materials due to its microphase-separated structure with alternately connected hard and soft segments. In this study, SMPU of different molecular weights were prepared with poly(caprolactone) diol (PCL), hexamethylene diisocyanate (HDI), 1, 6-hexanediamine (HMDA), trimethylolpropane tris (3-mercaptopropionate) (TMPMP), and Dilauroyl peroxide (LPO). LPO as a chemical cross-linking agent can induce secondary cross-linking, which leads to the formation of a strong and stable secondary cross-linking network, and this network can be transformed into a supplier of internal stresses, so that the network exhibits excellent bidirectional shape memory effects. The effects of thermal and shape memory properties were investigated by TGA, DSC and DMA tests, the phase transition temperature of the SMPU was studied and the shape recovery process was recorded. The results show that the SMPU synthesized by PCL2k has good shape memory performance, with a reversible strain of up to 16.1 %, and the average shape fixation and recovery rates of 92.83 % and 99.98 %, respectively, with good shape memory performance, which is expected to show a wide range of application prospects and value of use in the fields of smart fabrics, biomedicine, sensing drive, aerospace and so on.

中文翻译：

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基于LPO的二次交联网络结构温度响应型形状记忆聚氨酯的合成及性能


聚氨酯因其具有交替连接的硬链段和软链段的微相分离结构而成为形状记忆材料的极好的潜在候选者。本研究以聚己内酯二醇(PCL)、六亚甲基二异氰酸酯(HDI)、1, 6-己二胺(HMDA)、三羟甲基丙烷三(3-巯基丙酸酯)(TMPMP)和过氧化二月桂酰制备了不同分子量的SMPU。 （LPO）。 LPO作为化学交联剂，可以诱导二次交联，从而形成牢固而稳定的二次交联网络，并且该网络可以转化为内应力的提供者，从而使网络表现出优异的性能。双向形状记忆效应。通过TGA、DSC和DMA测试研究了热性能和形状记忆性能的影响，研究了SMPU的相变温度并记录了形状恢复过程。结果表明，PCL2k合成的SMPU具有良好的形状记忆性能，可逆应变高达16.1%，平均形状固定率和恢复率分别为92.83%和99.98%，具有良好的形状记忆性能，有望在智能织物、生物医学、传感驱动、航空航天等领域展现出广泛的应用前景和使用价值。