Effect of carbonization temperature on crystalline structure and properties of isotropic pitch-based carbon fiber

초록

Isotropic pitch-based fibers produced from coal tar pitch with the melt-blowing method were carbonized at temperatures ranging from 800 to 1600 degrees 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 degrees C probably due to randomization through the process of gas evolution; however, structural ordering eventually occurred at around 1400 degrees C. For the carbonized pitch powder without stabilization, structural ordering perpendicular to the graphene planes occurred at around 800-900 degrees 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.

키워드