Accession Number : AD0755351
Title : Polyacrylonitrile Precursor Fibers for Conversion to High-Modulus, High-Strength Fibers. Volume III. Some X-Ray Diffraction Considerations.
Descriptive Note : Research rept. Nov 70-Jul 71,
Corporate Author : AEROSPACE CORP EL SEGUNDO CALIF LAB OPERATIONS
Personal Author(s) : Brelant,Sam ; McDonald,Willard R.
Report Date : 12 JAN 1973
Pagination or Media Count : 24
Abstract : 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)
Descriptors : (*CARBON FIBERS, *X RAY DIFFRACTION), (*ACRYLONITRILE POLYMERS, X RAY DIFFRACTION), SYNTHETIC FIBERS, GRAPHITE, MECHANICAL PROPERTIES, OXIDATION, HEAT TREATMENT
Subject Categories : Physical Chemistry
Distribution Statement : APPROVED FOR PUBLIC RELEASE