Isotropic pitch-based fibers produced from coal tar pitch with the melt-blowing method were carbonized at temperatures ranging from 800 to 1600 o C to investigate their crystalline structure and physical properties as a function of the carbonization temperature. The in-plane crystallite size (L a ) of the carbonized pitch fiber from X-ray diffraction increased monotonously by increasing the carbonization temperature resulting in a gradual increase in the electrical conductivity from 169 to 3800 S/cm. However, the variation in the d 002 spacing and stacking height of the crystallite (L c ) showed that the structural order perpendicular to the graphene planes got worse in carbonization temperatures from 800 to 1200 o C probably due to randomization through the process of gas evolution; however, structural ordering eventually occurred at around 1400 o C. For the carbonized pitch powder without stabilization, structural ordering perpendicular to the graphene planes occurred at around 800-900 o C indicating that oxygen was inserted during the stabilization process. Additionally, the shear stress that occurred during the melt-blowing process might interfere with the crystallization of the CPF.

No abstract

No abstract