High‐Performance Silicone Rubber Composites With Improved Electrical Conductivity and Mechanical Properties Using Copper‐Modified CNT

ABSTRACT To address the need for high‐performance conductive composites in flexible electronics, this study developed a novel silicone rubber composite reinforced with copper‐plated carbon nanotubes. A uniform and dense metallic copper coating was successfully constructed on the nanotubes through a combined process of acid oxidation and palladium‐catalyzed chemical plating. This coating not only serves as an effective thermal barrier, enhancing the composite's thermal stability but also enables synergistic performance enhancement through optimized interfacial design. Electrically, the copper‐plated nanotubes form an efficient three‐dimensional conductive network within the silicone rubber matrix, allowing the composite's conductivity to be precisely tuned across three orders of magnitude, from 8 × 10 −3 S/m at low loading to 5 × 10 1 S/m at high loading. Mechanically, the rigid metallic coating transforms the nanotubes into an effective reinforcing phase, providing strong interfacial bonding and resulting in a maximum tensile strength of 4.3 MPa at optimal loading, along with significantly improved Young's modulus and hardness. This work demonstrates that surface metallization is an effective interfacial strategy for developing multifunctional elastomers, showing particular promise for applications requiring both reliable conductivity and mechanical durability.