In situ coupled mechanical/electrical/WAXS/SAXS investigations on EPDM-based composite materials filled with carbon black (CB) have been performed under uniaxial tensile stretching. The time-resolved correlation between the electrical conductivity and the microstructural state of the composite reveals the mechanisms governing the structure/properties relationships with increasing deformation: orientation of the EPDM chains with reorganization of the CB network and ultimately, nano-cavitation. This involvement of different microstructural phenomena offers a comprehensive picture of the mechanisms underlying the non-monotonic evolution of the electrical conductivity with strain. At large deformations, the formation of nanovoids preceding the material fracture induces by a significant decrease in conductivity. Our study thus brings new light on the conductivity/strain relationships of carbon black filled elastomers. We envision potential applications in developing smart rubber materials where microstructural changes preceding material rupture can be monitored in situ by coupled electrical measurements.

原位已在单轴拉伸拉伸下对填充炭黑 (CB) 的 EPDM 基复合材料进行机械/电气/WAXS/SAXS 耦合研究。复合材料的电导率和微结构状态之间的时间分辨相关性揭示了随着变形的增加控制结构/性能关系的机制：EPDM 链的取向与 CB 网络的重组以及最终的纳米空化。不同微观结构现象的这种参与提供了对电导率随应变非单调演化的机制的全面描述。在大变形时，材料断裂前纳米空隙的形成会导致电导率显着降低。因此，我们的研究为炭黑填充弹性体的电导率/应变关系带来了新的启示。我们设想在开发智能橡胶材料方面的潜在应用，可以监测材料破裂前的微观结构变化通过耦合电测量就地进行。