一种离子聚合物金属复合材料拉伸试验研究

 离子聚合物金属复合材料（IPMC）是一种新型的电致激活功能材料。为了研究IPMC的驱动特性，需要掌握其基本力学性能。通过化学镀方法，在一种与Nafion 117相似的离子交换膜表面镀金属铂（Pt），制备了IPMC拉伸试样；测定了不同含水量情况下，IPMC试样尺寸的变化；通过拉伸试验和扫描电镜（SEM）形貌观察，研究IPMC含水量与拉伸性能之间、含水量与弹性模量之间的变化关系。研究表明：在聚合物基底溶胀状态下，试样各向尺寸变化相同，IPMC的弹性模量随其含水量的增加而降低，呈幂指数趋势下降；针对表面金属（Pt）镀层厚度为5~20 μm的IPMC试样，表层金属产生龟裂，且Pt元素在厚度方向上分布不均匀，若仍采用层合板理论对其弹性模量进行预测，将导致较大的误差。本文结果可为IPMC的力学建模、失效形式等研究提供有益的参考。

Experimental Research on IPMC Material Tensile Samples

Ionic polymer metal composites（IPMC）are a new kind of electro-active material. It is necessary to study their essential mechanical properties for an understanding of their driving characteristics. The IPMC tensile samples are prepared by electroless plating, and an ionic exchange polymer which is similar to Nafion 117 is plated by platinum. The changes of sample geometrical dimensions are measured in different water contents. In this article, the relationships between the tensile capabilities, elastic modulus and water content of the samples are investigated by tensile testing, and their sectional and surface morphology are analyzed by scanning electron- microscope(SEM). The results show that: in swelling the changes of geometrical dimensions are identical in all directions; as the water content increases the elastic modulus decrease in the form of power series; the surface layer of the plating metal（Pt）is chapped when the thickness is 5-20 μm, and the distribution of Pt contents on sample cross section is asymmetric; therefore, if the laminate theory is introduced in predicting the elastic- modulus, it would obviously lead to errors in the calculated results. The research conclusions are of value for mechanical modeling and failure analysis on IPMC.