TPU/CNT导电泡沫力电耦合效应的原位CT实验研究  

In-situ CT experimental investigation on the electro-mechanical properties of a TPU/CNT conductive foam

作　　者：刘昕 柴海伟 范端 黄俊宇 LIU Xin;CHAI Haiwei;FAN Duan;HUANG Junyu(The Peac Institute of Multiscale Sciences,Chengdu 630031,Sichuan,China)

机构地区：[1]顶峰多尺度科学研究所,四川成都630031

出　　处：《实验力学》2022年第6期829-837,共9页Journal of Experimental Mechanics

基　　金：国家自然科学基金(No.11802252)资助。

摘　　要：由掺杂了碳纳米管(CNT)的热塑性聚氨酯(TPU)所制成的导电泡沫材料(TPU/CNT)是一种力电性能优异的新型功能型复合材料。为探究其力电耦合效应,依托上海同步辐射光源搭建了准静态加载下的原位多维(力、电、结构)CT表征系统。在施加压缩载荷的同时,实时采集了应力-应变-电阻曲线以及三维孔洞结构的演化过程。利用回转张量分析方法量化了孔洞三维形貌统计特征的演化过程,同时追踪了试样内典型孔洞的坍塌过程。结果表明,导电泡沫在压缩加载下,孔洞通过边角压实、胞壁屈曲等方式发生坍塌,胞壁及其内CNT相互接触,使得试样内部导电通路增加,在宏观上表现为试样电阻随压缩应变线性下降。相关技术和研究成果可为导电泡沫的材料及传感器设计与工程应用提供参考。Carbon-nanotube(CNT) doped thermoplastic polyurethane(TPU) conductive foams are a new class of functional composites with excellent mechanical and electrical properties. To explore the electro-mechanical properties of TPU/CNT, an in-situ, multidimensional(force, resistance and structure) CT characterization system for quasi-static loading was built based on the Shanghai synchrotron radiation facility. Upon compression, the evolution processes of stress-strain-resistance curves and three-dimensional cellular structures were recorded in real time. The statistical characteristics of the three-dimensional morphologies of pores were quantified via gyration-tensor analysis, and the collapse process of typical pores in the sample was tracked. The results show that under compressive loading, pores in the sample collapse via compaction of lateral edges and buckling of cell walls. Therefore, the cell walls along with CNTs inside contact with each other, resulting in an increase in the conduction paths across the sample. At the macroscopic scale, the resistance of the sample decreases linearly with the compressive strain. The technique and results can provide suggestions for the design and engineering application of conductive foam materials and related sensors.

关 键 词：导电泡沫 原位显微CT 力电耦合 孔洞坍塌 

分 类 号：O341[理学—固体力学]