||Surface Characterization of Sized and Desized Toray M40J Carbon Fibers
||Proc. 47th Intl. SAMPE Symp. and Exhib.
||Allred, R. E.; Wesson, S. P.; McCorkle, L.; Sutter, J. K.; Wheeler, D. R.
||To increase the durability of high-temperature composites, it is necessary to optimize wetting and interfacial bonding between high-modulus carbon fibers and high-temperature polyimide resins. It has been previously demonstrated that the electro-oxidative shear treatments used by fiber manufacturers are not effective on higher modulus fibers that have fewer edge and defect sites in the surface crystallites. In addition, sizings commercially supplied on most carbon fibers are not compatible with polyimides. This study was undertaken to characterize the surface chemistry and energy of Toray M40J and M60J carbon fibers and typical fluorinated polyimide resins. The fibers were characterized with and without sizing. The carbon fibers were characterized using single filament wetting, scanning electron microscopy, and x-ray photoelectron spectroscopy measurements. The polyimide matrix resins were coated onto glass filaments for characterization by wetting measurements. Surface energy components were obtained by wetting with nondispersive (methylene iodide), acidic (ethylene glycol), and basic (formamide) probes. Data generated will be used to guide subsequent work for modifying fiber surface chemistry to improve wetting and bonding with polyimides of interest.
||desize, carbon fibers, sizing, surface chemistry, surface energy, durability, high-temperature, interfacial bonding, polyimide, surface crystallites, fluorinated polyimide