Lu Hai-Feng, Wang Meng, Chen Xu-Man, Lin Bao-Ping, Yang Hong
School of Chemistry and Chemical Engineering, Jiangsu Province Hi-Tech Key Laboratory for Bio-medical Research, State Key Laboratory of Bioelectronics, Institute of Advanced Materials , Southeast University , Nanjing 211189 , China.
J Am Chem Soc. 2019 Sep 11;141(36):14364-14369. doi: 10.1021/jacs.9b06757. Epub 2019 Aug 30.
Liquid-crystal elastomer (LCE) materials, which have been developed and investigated for 4 decades, still lack real industrial applications. The fundamental obstacle is the modest force of LCEs generated in the LC-to-isotropic phase transition process, which is the most important actuation moment. Here, we report an interpenetrating liquid-crystal polyurethane/polyacrylate elastomer material, consisting of one main-chain polyurethane LCE and another liquid-crystal polyacrylate thermoset network, which are simultaneously polymerized. This two-way shape memory material can reversibly shrink/expand under thermal stimulus and show ultrastrong actuation-mechanics properties. With a maximum shrinkage ratio of 86% at 140 °C, which is beyond the LC-to-isotropic phase transition, its actuation blocking stress, actuation work capacity, breaking strength, and elastic modulus reach 2.53 MPa, 1267.7 kJ/m, 7.9 MPa, and 10.4 MPa, respectively. Such LCE material can lift up a load 30 000 times heavier than its own weight. We hope the outstanding mechanical properties of this interpenetrating polymer network-LCE material would pave the way for real industrial utilizations of LCE-based soft actuators.
液晶弹性体（LCE）材料已经历了40年的研发与研究，但仍缺乏实际的工业应用。其根本障碍在于LCE在液晶相向各向同性相转变过程中产生的力较小，而这一过程是最重要的驱动时刻。在此，我们报道了一种互穿型液晶聚氨酯/聚丙烯酸酯弹性体材料，它由一种主链聚氨酯LCE和另一种液晶聚丙烯酸酯热固性网络组成，二者同时聚合而成。这种双向形状记忆材料在热刺激下能够可逆地收缩/膨胀，并展现出超强的驱动力学性能。在140°C时其最大收缩率为86%，超过了液晶相向各向同性相的转变温度，其驱动阻塞应力、驱动功能力、断裂强度和弹性模量分别达到2.53 MPa、1267.7 kJ/m、7.9 MPa和10.4 MPa。这种LCE材料能够提起比自身重量重30000倍的负载。我们希望这种互穿聚合物网络-LCE材料的优异力学性能能够为基于LCE的软驱动器的实际工业应用铺平道路。
