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Gel Spun PAN/CNT Based Carbon Fibers with Honey-Comb Cross-Section
Final technical rept. 15 Aug 2010-14 Aug 2013
GEORGIA INST OF TECH ATLANTA SCHOOL OF MATERIALS SCIENCE AND ENGINEERING
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The density of currently produced polyacrylonitrile based carbon fibers is around 1.8 gcm3. It will be of great benefit to reduce this density so that the high-performance structures made from such fibers can be lighter than those made from the solid carbon fibers. With the goal to produce high-strength and high-modulus carbon fibers with densities in the range of 0.9-1.3 gcm3, polyacrylonitrile PAN based precursor fibers were produced with a honeycomb structure. Using dry jet wet spinning method, honeycomb precursor fibers were manufactured that consisted of PAN as the sea component and polymethyl methacrylate as the islands component. Subsequently, the precursor fibers were stabilized and carbonized to produce hollow carbon fibers. Resulting carbon fibers possessed the estimated density in the range of 1.1 to 1.2 gcm3 with tensile modulus in number of trials in the range of 300 to 368 GPa. By comparison, modulus of IM7 fiber with a density of about 1.78 gcm3 is 276 GPa. Thus the specific modulus of the hollow carbon fiber can be more than 50 higher than that of state of the art PAN based carbon fiber such as IM7. In addition, a number of other studies on structure, processing, and properties of polymerCNT composite films and fibers were also conducted. Results of these studies are well documented in the many archival publications and two completed Ph.D. theses. These publications and thesis are listed below. Amongst the key additional findings include nanocomposite fibers with thermal conductivity in the range of 2 15 Wmk. Details of the unpublished work of the honey-comb fiber are included with this report.
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