Preparation and Application of Ultra-thin Carbon (graphite) Ribbon

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A mesophase pitch of 100% anisotropy prepared from methylnaphthalene using HF/BF_3 was spun through the slit-shaped nozzle in a temperature range of 260-275ﾟC.Very thin fibers were obtained, about 2-5mum in thickness and 10-18mum in width, according to spinning temperatere. The slit-shaped transversal section of tape was observed under optical microscope, scanning, and transmission electron microscopes. The symmetric Double Layr is proposed as a model of the cross-sectional texture, which carried radial orientation at the semicircular edges, onion-skin at the flat edges, alignments perpendicular to the flat edges in the intermediate parts, and aligunments parallel to the major axis at the central part of the ellipse fiber. Present carbon fibers exhibited better mechanical properties, as compared to those of round fibers spun through conventional circular nozzles. The fibers after graphitization at 2500ﾟC showed excellent tensile stength modulus as high as 340-395Kg/mm^2 and 84-92ton/mm^2, respectively. The particular shape and texture of transversal scction appears principally responsible for such tensile propertics.