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Polyacrylonitrile Precursor Fibers for Conversion to High-modulus, High-strength Fibers

其他書名	Some X-ray diffraction considerations
出版	Space and Missile Systems Organization, Air Force Systems Command, 1973
URL	http://books.google.com.hk/books?id=qVG3tgAACAAJ&hl=&source=gbs_api

註釋An attempt was made to utilize Debye-Scherrer x-ray diffraction patterns to demonstrate the relationship between the apparent degree of molecular orientation of a polyacrylonitrile precursor and the final graphite crystallite orientation in high-performance graphite fibers. In the case of specially prepared fibers with extremely high orientation followed by crosslinking with ionizing radiation, some retention of orientation was evident through all processing steps. The apparent orientation retention, however, was less than that anticipated and inadequate in itself to confirm the postulated mechanims invoking retention of the chain-extended crystal structure through the thermal decomposition. An alternature mechanism of chemical 6cyclization6 consistent with the apparent morphology has already been proposed. (Author-PL)