SBIR-STTR Award

This Small Business Technology Transfer Research Phase I program will test a processing scheme for introducing exceptional electrical conductivity to a class of high-temperature, high-strength polymer fibers. This class of polymer fibers include poly (p-phenylene terephthalamide) (PPTA), poly (p-phenylene benzobisthiazole) (PBZT) and poly (p-phenylene benzobisoxazole) (PBO). The polymer fibers are prepared from their nematic liquid crystalline solutions under a very high extensional flow. Therefore, they exhibit extremely high molecular orientation and tensile mechanical properties. In this Phase I research program, metal precursors will be incorporated into the high-performance polymer fibers and subsequently reduced to form a continuous network of the highly conductive metal in the fiber matrix giving rise to the conductivity. The proposed processing scheme is fully in line with the commercial production of these polymer fibers. The resulting conductive metal-containing polymer fibers are expected to have advantages over conductive metal wires in flexibility, weight savings, mechanical strength and durability, tailored electrical conductivity and more uniform electromagnetic interference (EMI) shielding as well as advantages over metal-coated conductive polymer fibers in thermal and mechanical durability and EMI shielding at low frequencies. They have great potential for applications in automobiles and space aerospace vehicles, where flexibility, weight savings and mechanical durability are important

This Small Business Technology Transfer Research Phase II program will implement an integrated processing scheme to produce high-strength, high-modulus conductive metal-containing poly(p-phenylene benzobisoxazole)(PBO)fiber for power and signal transfer and electromagnetic interference (EMI) shielding applications in space and aerospace vehicles. The Phase I program has demonstrated that metal precursors can be readily infiltrated into PBO fiber during coagulation and in-situ reduced by a chemical method to form a highly conductive metal network in the fiber matrix. The kinetics of the metal infiltration and reduction is compatible with the rate of commercial production of PBO fiber. In this Phase II program, PBO dopes in kilogram quantities will be prepared for producing the conductive PBO fiber with the integrated processing scheme. This processing scheme enables full control of the processing conditions during each step of the fiber preparation, leading to the optimization of the mechanical and electrical properties of the PBO fiber. It is expected that the metal-containing PBO fiber will have advantages over metal wires in weight savings, mechanical flexibility, durability and strength. It will also have improved shielding ability at low frequencies and wear resistance in thermal and mechnaical cycles over the metal-clad Aracona fibers