具有预置结构介电弹性体的制备、结构与性能研究

Dielectric elastomer mcrio-driver has attracted increasing focus owing to its application value in many fields. Further improvement and optimization of the electrostrictive strain performance of dielectric elastomer is the main problem faced in the application as a micro-driver. Currently, the method that enhancing dielectric constant or reducing modulus of composites is used to improve the electrostrictive strain performance. And only a small amount of researches have focused on the effect of internal structure on the performance. Nevertheless，the used method to moderate the internal structure of composite such as stretching has limited acceleration on material’s properties, because all of them are the fine-tuning methods based on the basic structures of composite material. In this proposal, the structure control is realized before the formation of basic structures via the electric field-induced orientation of nano-particle filler and the fabrication of an ordered structure in the uncured matrix. Then the dielectric elastomer with preseted structure is obtained after curing the matrix. The controlled factors of the electric responsiveness of nano-particle filler and the influence mechanism of electric parameters on the preseted ordered structure are explored. Consequently, relevance of the preseted ordered structure of dielectric elastomer and its electrostrictive strain performance is revealed, which provide and expand the preparation method of high performance dielectric elastomer.

介电弹性体微驱动器因在众多领域具有应用价值而引起人们广泛关注。进一步提高和优化电致应变性能是介电弹性体作为微驱动器进行应用所面临的主要问题。目前致力于提高电致应变性能的方法多为单纯提高材料介电常数或降低材料模量，仅有少量研究是通过调控材料内部结构进行的。而且，所采用的拉伸等调控结构的方法都是在已形成的基础结构上进行的微调，对材料宏观性能的改善作用有限。本项目提出在基础结构形成前进行结构调控，即利用电场诱导填充粒子在未固化基体中排列取向，构建有序结构，固化后制得具有预置结构的介电弹性体，探究填充粒子电场响应性的受控因素，以及材料复合过程中电场参数等对预置有序结构的影响机制，揭示介电弹性体内部预置有序结构与材料电致应变性能的关系，为高电致应变介电弹性体的制备方法提供有益补充。

介电弹性体微驱动器因在众多领域具有应用价值而引起人们广泛关注。进一步提高和优化电致应变性能是介电弹性体作为微驱动器进行应用所面临的主要问题。本项目围绕利用电场诱导填充粒子在未固化基体中排列取向，构建有序结构制备具有预置结构的介电弹性体。设计并制备了2类电场响应性复合粒子，研究了其在电场诱导下的排列行为，探究了填料粒子在介电弹性体基体中排列程度的影响因素和形成机制，并通过与材料的介电、力学性能的结合，阐明了电致形变性能与结构之间的相关性。本项目研究结果表明：电场响应性复合粒子在电场诱导极化作用下，随着填充量增加，场强升高，颗粒排列程度增强；与不加电场相比，在制备介电硅橡胶过程中施加外部电场可以提升材料的介电常数，而模量呈相反变化趋势，所得介电弹性体最大电致形变量提升1.7倍，同样使电致形变量达到10%，刺激电场强度由11V/μm降至5.5V/μm。而施加垂直方向电场制备介电弹性体时，所得介电硅橡胶的模量高于施加水平方向电场的情况，但介电常数的提升明显高于水平电场的，而材料电致形变性能远优于施加水平方向电场制备的介电硅橡胶，最大电致形变量达到16%@5V/μm，当施加2.8V/μm的刺激电场时，形变量即可达到10%。通过本项目的实施，探索出了一种利用电场调控介电填料在弹性体基体中分布制备具有预置结构介电弹性体的方法，丰富了低电场强度下产生高电致形变介电弹性体的制备方法。