Thiol-Acrylate Main-Chain Liquid-Crystalline Elastomers with Tunable Thermomechanical Properties and Actuation Strain
Thiol-Acrylate Main-Chain Liquid-Crystalline Elastomers with Tunable Thermomechanical Properties and Actuation Strain
复制标题
DOI：
10.1002/polb.24249
复制
发表时间：
2017-01-15
影响因子：
--
通讯作者：
Yakacki, Christopher M.
中科院分区：
文献类型：
--
作者：
Saed, Mohand O.;Torbati, Amir H.;Yakacki, Christopher M.
本研究旨在探讨交联对液晶弹性体热机械行为之影响。通过硫醇-丙烯酸酯迈克尔加成反应合成了主链LCE网络。该反应的稳健性质允许通过改变交联剂的浓度和官能度来定制LCE的行为。各向同性橡胶模量、玻璃化转变温度和失效应变显示出对交联剂浓度的强烈依赖性，并且范围分别为0.9 MPa、3 ℃和105%至3.2 MPa、25 ℃和853%。显示各向同性转变温度（T1）受交联剂的官能度影响，对于三官能和四官能交联剂，范围为70 ° C至80 ° C。可以通过控制交联剂的量和施加的应力来调整致动的幅度。致动增加，增加所施加的应力和减少与更大量的交联。在100 kPa的偏置应力下实现的最大应变驱动为296%，这导致最低交联网络的工作能力为296 kJ/m3。总的来说，实验结果提供了一个基本的洞察力，连接热机械性能和致动的均匀多畴电致伸缩网络的序参数为0.80时，拉伸。(C)2016 Wiley Periodicals，Inc.
The purpose of this study was to investigate the influence of cross-linking on the thermomechanical behavior of liquid-crystalline elastomers (LCEs). Main-chain LCE networks were synthesized via a thiol-acrylate Michael addition reaction. The robust nature of this reaction allowed for tailoring of the behavior of the LCEs by varying the concentration and functionality of the cross-linker. The isotropic rubbery modulus, glass transition temperature, and strain-to-failure showed strong dependence on cross-linker concentration and ranged from 0.9 MPa, 3 degrees C, and 105% to 3.2 MPa, 25 degrees C, and 853%, respectively. The isotropic transition temperature (T-i) was shown to be influenced by the functionality of the cross-linker, ranging from 70 degrees C to 80 degrees C for tri- and tetra-functional cross-linkers. The magnitude of actuation can be tailored by controlling the amount of cross-linker and applied stress. Actuation increased with increased applied stress and decreased with greater amounts of cross-linking. The maximum strain actuation achieved was 296% under 100 kPa of bias stress, which resulted in work capacity of 296 kJ/m(3) for the lowest cross-linked networks. Overall, the experimental results provide a fundamental insight linking thermomechanical properties and actuation to a homogenous polydomain nematic LCE networks with order parameters of 0.80 when stretched. (C) 2016 Wiley Periodicals, Inc.