Fabrication of Conductive Metal-Containing Polymer Fibers and Sheets (251)

Electrical wires are made of highly conductive metals such as copper and silver. They afford the highest conductivity for power, signal, and electromagnetic interference (EMI) shielding applications. However, their high density, low mechanical strength, and poor durability in mechanical cycles have made them undesirable for use in space and aerospace vehicles where weight saving and vibration are of prime concern. Recent developments in the area of electrically conducting polymers have created a class of conjugated polymers, such as polyacetylene, polythiophene, and polypyrrole. These polymers can be introduced into the production process with high conductivity by chemical and electrochemical doping. Unfortunately, the doped conjugated polymers are environmentally unstable and, therefore, have few practical applications.

The University of Dayton Research Institute, in conjunction with Syscom Technology, Inc. and the Air Force Materials Directorate, has developed a process for fabricating highly-conductive, metal-containing polymer fibers and sheets with excellent mechanical properties. In this hybrid material, the metal forms a continuous network, giving rise to high conductivity while the polymer provides the mechanical strength and durability. This process can be readily incorporated into the production of high-performance polymeric fibers such as DuPont's Kevlar®, Toyobo's Zylon®, and Akzo-Nobel's M5®. These fibers offer a tensile strength of 400-800 KSI and a Young's modulus of 25-50 MSI.

The conductive, metal-containing polymer fibers and sheets are excellent materials for signal and EMI shielding applications. Their conductivity can be tailored to greater than 104 S cm-1 and is stable up to 300ºC. Owing to their small diameter and mechanical strength, the metal-containing polymer fibers provide more uniform EMI shielding and better protection to the core conductor than large metal wires. They are expected to have improved EMI shielding at low frequencies because the newly-developed materials contain metals that interpenetrate the fiber structure, forming an integral conductive network. This interpenetrating network structure allows the metal-containing fibers to have more durable conductivity in thermal and mechanical cycles.

U.S. Patent Application 09/232,931 filed January 19, 1999.

For more information, please contact the Office for Technology Partnerships at 937-229-3515.

Return to Technologies Available for Licensing.