High-Strain Shape-Memory Polymers
High-Strain Shape-Memory Polymers
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DOI：
10.1002/adfm.200901409
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发表时间：
2010-01-08
影响因子：
19
通讯作者：
Gall, Ken
中科院分区：
文献类型：
--
作者：
Voit, Walter;Ware, Taylor;Gall, Ken
形状记忆聚合物 (SMP) 是一种自我调节的智能材料，可以在特定的定制温度下精确控制形状变化。在这项研究中，通过合成丙烯酸甲酯(MA)、甲基丙烯酸甲酯(MMA)和丙烯酸异冰片酯(IBoA)的共聚物，将玻璃化转变温度(T-g)调整在28至55℃之间。具有以摩尔百分比分数优化的交联剂密度和光引发剂浓度的丙烯酸酯组合物表现出完全可恢复的应变，28℃的T-g为807%，37℃的T-g为663%，55℃的T-g为553%。一种新化合物，4,4'-二(丙烯酰氧基)苯偶酰(下文称为Xini），其中可聚合功能和引发功能被纳入同一分子中，被合成并聚合成丙烯酸酯形状记忆聚合物，其经过热机械表征，产生超过 500% 的完全可恢复应变。这项工作中合成的材料与行业标准热塑性 SMP（三菱的 MM5510）进行了比较，后者显示出类似程度的失效应变，但没有完全形状恢复：单个形状记忆循环后的残余应变导致大规模变形。本研究中的材料旨在实现未来的应用，这些应用既需要可恢复的高应变能力，又需要准确、独立地定位 T-g 的能力。
Shape-memory polymers (SMPs) are self-adjusting, smart materials in which shape changes can be accurately controlled at specific, tailored temperatures. In this study, the glass transition temperature (T-g) is adjusted between 28 and 55 degrees C through synthesis of copolymers of methyl acrylate (MA), methyl methacrylate (MMA), and isobornyl acrylate (IBoA). Acrylate compositions with both crosslinker densities and photoinitiator concentration optimized at fractions of a mole percent demonstrate fully recoverable strains at 807% for a T-g of 28 degrees C, at 663% for a T-g of 37 degrees C, and at 553% for a T-g of 55 degrees C. A new compound, 4,4'-di(acryloyloxy)benzil (referred to hereafter as Xini) in which both polymerizable and initiating functionalities are incorporated in the same molecule, was synthesized and polymerized into acrylate shape-memory polymers, which were thermornechanically characterized yielding fully recoverable strains above 500%. The materials synthesized in this work were compared to an industry standard thermoplastic SMP, Mitsubishi's MM5510, which showed failure strains of similar magnitude, but without full shape recovery: residual strain after a single shape-memory cycle caused large-scale disfiguration. The materials in this study are intended to enable future applications where both recoverable high-strain capacity and the ability to accurately and independently position T-g are required.