Fejős Márta, Molnár Kolos, Karger-Kocsis József
Department of Polymer Engineering, Faculty of Mechanical Engineering, Budapest University of Technology and Economics, Muegyetem rkp. 3., Budapest H-1111, Hungary.
MTA-BME Research Group for Composite Science and Technology, Muegyetem rkp. 3., Budapest H-1111, Hungary.
Materials (Basel). 2013 Oct 9;6(10):4489-4504. doi: 10.3390/ma6104489.
Triple-shape memory epoxy (EP)/polycaprolactone (PCL) systems (PCL content: 23 wt %) with different structures (PCL nanoweb embedded in EP matrix and EP/PCL with co-continuous phase structure) were produced. To set the two temporary shapes, the glass transition temperature () of the EP and the melting temperature () of PCL served during the shape memory cycle. An attempt was made to reinforce the PCL nanoweb by graphene nanoplatelets prior to infiltrating the nanoweb with EP through vacuum assisted resin transfer molding. Morphology was analyzed by scanning electron microscopy and Raman spectrometry. Triple-shape memory characteristics were determined by dynamic mechanical analysis in tension mode. Graphene was supposed to act also as spacer between the nanofibers, improving the quality of impregnation with EP. The EP phase related shape memory properties were similar for all systems, while those belonging to PCL phase depended on the structure. Shape fixity of PCL was better without than with graphene reinforcement. The best shape memory performance was shown by the EP/PCL with co-continuous structure. Based on Raman spectrometry results, the characteristic dimension of the related co-continuous network was below 900 nm.
制备了具有不同结构（聚己内酯（PCL）纳米网嵌入环氧树脂（EP）基体以及具有双连续相结构的EP/PCL）的三形状记忆环氧（EP）/聚己内酯（PCL）体系（PCL含量：23 wt%）。在形状记忆循环过程中，利用EP的玻璃化转变温度（ ）和PCL的熔点（ ）来设定两种临时形状。在用真空辅助树脂传递模塑法将EP渗透到纳米网之前，尝试用石墨烯纳米片增强PCL纳米网。通过扫描电子显微镜和拉曼光谱对形态进行分析。通过拉伸模式下的动态力学分析确定三形状记忆特性。石墨烯还被认为可作为纳米纤维之间的间隔物，提高EP的浸渍质量。所有体系中与EP相相关的形状记忆性能相似，而属于PCL相的形状记忆性能则取决于结构。未添加石墨烯增强时PCL的形状固定性更好。具有双连续结构的EP/PCL表现出最佳的形状记忆性能。基于拉曼光谱结果，相关双连续网络的特征尺寸低于900 nm。
