Stretchable conductor based on carbon nanotube/carbon black silicone rubber nanocomposites with highly mechanical, electrical properties and strain sensitivity

Stretchable conductive polymer composites are important in the field of flexible electronic devices, in which stretchable conductive silicone rubber composites has drawn great attention. However, the poor mechanical properties of the SR composites limit their practical application. How to compensate this drawback without compromising its electrical conductivity is an issue deserved to investigate. Herein, conductive carbon black grafted with a silicone coupling agent was prepared by free radical polymerization, and further reacted with carbon nanotube to obtain a new carbon black-carbon nanotube hybrid filler. This hybrid filler can not only improve the mechanical properties of silicone rubber composites, but also greatly enhance their electrical conductivity. Consequently, a silicone rubber composite with 5.76 vol% hybrid filler has high tensile strength (4.5 MPa) and elongation at break (211%). The minimum conductive percolation threshold and maximum conductivity of the composite are 0.24 vol% and 248.8 S/m, respectively. Besides, the composite has high strain sensitivity and superior deformation recovery performance, and can be applied to detect human motion behavior under a low strain. The preparation method of the hybrid filler provides a novel approach to the preparation and production of stretchable conductive composites with good mechanical properties and potential application for flexible electronic devices.