Processing and Characterization of Experimental Carbon Fiber

This collaborative project between the Naval Research Lab (NRL) and the University of Kentucky Center for Applied Energy Research (CAER) will focus on the processing and characterization of experimental carbon fiber. The proposed collaborative effort is specifically unique, in that, NRL has extensive expertise in polymer synthesis with novel focus on carbon fiber precursor polymer, and CAER has unique capabilities on the processing and characterization side, necessary for carbon fiber production and evaluation. Specifically NRL will supply CAER with experimental polymer precursor powder. CAER will process the polymer into precursor fiber, from which carbon fiber will be produced and characterized. CAER will provide NRL the final carbon fiber properties, and full characterization (tensile strength, modulus, 4-point electrical resistivity, etc.) of the experimental carbon fiber, along with processing details. Frequent communication, in the form of weekly or bi-weekly telecoms between NRL and CAER will expedite the carbon fiber development process. Given the extensive, unique expertise of both parties, timely progression of carbon fiber development is expected. For each experimental polymer, CAER will provide a detailed report of all processing and property data - to include processing and carbon fiber properties. UK CAER Unique Capabilities: 1) Only fully-commissioned, bench-scale, multifilament wet-spinning line for precursor fiber in the U.S. (apart from industry)[1] 2) Carbonization temperatures up to 2700 °C[2-4] 3) Staffed by U.S. scientists, engineers (and graduate students) each with over 10 years experience in carbon fiber development[1, 2, 5-11] The University of Kentucky Center for Applied Energy Research is, to the author's knowledge, the only research center to maintain and operate, on-site, a fully commissioned (2007), bench-scale (100 ft long) multifilament polyacrylonitrile (PAN) precursor fiber spinning line housed in a secure 5000 ft2 facility (apart from industry). Figure 1 shows a pictorial view of the line. This scale of the line was purpose-built to balance the production of meaningful research quantities of precursor tow (up to 1 lb/working day) while minimizing the time and effort necessary for line change-over. In this way, the line efficiently tests the "spinnability" of numerous experimental precursor dopes, which we prepare in-house, as well as produces sufficient fiber for subsequent thermal processing. Another of the unique values of the line is the ability to dial-in processing parameters of experimental dopes on a small scale, tuning in the spinning parameters on-the-fly. Further, the spinning technologies employed are readily transferrable to industry. CAER also has the proven capability to carbonize fibers up to graphitization temperatures. This is achieved by fixing the fiber tow in a purpose-built graphite tensioning fixture, followed by heating, in a He atmosphere to temperatures up to 2700°C. Figure 2 shows the graphite fixture and furnace used to achieve such high heat treatment temperatures. Lastly, as mentioned above, CAER has extensive experience in the field of carbon fiber development, particularly from PAN-based precursor fiber (see references listed above in UK CAER Unique Capabilities). The sensible flow of this project will consist of, chronologically, a fiber spinning portion (Part One), followed by a carbon fiber processing and characterization portion (Part Two). To achieve pertinent results as timely as possible, effort will be primarily focused on parts one and two, as indicated in the project timeframe and budget. Lastly, effort will be directed towards reporting and following up for refinement of processing and characterization (Part Three).