This Small Business Technology Transfer Research (STTR) Phase II project has the overall objective of developing a multi-component melt spinning approach to produce a new family of high performance fibers using standard low-cost polymers. The new high-strength and/or high-modulus polymeric fiber is to be made using cutting-edge but commercially available spinning technology and an innovative and previously unexplored set of spinning process parameters. The resulting new fiber will be comparable in performance to other high-performance fibers on the market today, but will cost significantly less. Spinning experiments will be conducted at both the laboratory/bench scale, and at the pilot line level. Experimental fiber spinning lines will be modified to enable consistent fiber manufacturing. Produced fibers will be characterized using a variety of tools (focused ion beam, scanning and transmission electron microscopy, X-ray, tensile, lateral compression, density, differential scanning calorimetry, and dynamic mechanical analysis) to understand the new mechanisms that lead to improved strength and/or stiffness. The spinning conditions which enable these mechanisms will be optimized to meet target strength and/or stiffness goals. The possibility of introducing UV-resistant additives and/or other application-specific components, and any corresponding effects on performance, will also be studied. The broader impact/commercial potential of this project is based on achieving a performance goal for the new fibers of tenacity > 15 gf/denier and/or an initial modulus of 400 gf/denier or greater. Given the anticipated capability for low-cost high-volume production, these new fibers will have a cost approaching that of standard high tenacity industrial fibers (~ $7/lb) as compared to the typical >$20/lb for specialty high performance fibers such as aramids and high-performance polyethylene (HPPE). The new fiber products will be designed to have a performance above current high-tenacity industrial fibers (HT polyester and nylon) but below current specialty high-performance fibers (aramids, HPPE). The reduced cost for these fibers will result in lower costs over a variety of applications, which will benefit society (for example, by the greater proliferation of cut-resistant apparel and other safety/protective devices). In addition to these economic benefits, the proposed work will provide extensive characterization of nano-scale fibers that will contribute to the scientific understanding of polymeric fiber structure and behavior.
