Rheostructural studies of mesophase pitch using WAXD and OM

摘要

The properties of pitch-based carbon fibers are known to depend on the microstructure developed during the melt-spinning process [Edie, 1998]. Therefore, a fundamental understanding of flow and its influence on the microstructure is required to obtain carbon materials with desired properties. Numerous studies, both in situ and ex situ, have been performed on liquid-crystalline polymers to understand the evolution of microstructure and orientation by optical microscopy (OM) [Mather et al., 2000] and wide angle X-ray diffraction (WAXD) [Ugaz et al, 2001]. Unfortunately, due to the opacity of pitch, real-time microscopic studies cannot be performed on mesophase pitches; instead, offline and refiected-mode optical microscopy on solidified pitch samples has been used to characterize the microstructure. The effect of shear flow on the microstructure of mesophase pitch has been studied in literature [Cato and Edie (2003)].