Enhancing physical properties of mesophase pitch-based graphite fibers by modulating initial stabilization temperature

The development of carbon structures in mesophase pitch fibers was studied with controlling the initial temperature (T-i) of the stabilization process to optimize the mechanical properties of final carbon/graphite fibers. To understand the relationship between T-i and chemical structural change by thermostabilization, the pitch fiber was thermally treated from various T(i)s up to 350 degrees C with an elevation rate of 2 degrees C/min. Various analyses of the oxygen species in the fiber revealed that changing T-i governed the amount and distribution of oxygen in the stabilized fibers, while determining the effective duration of thermostabilization and preserving hydroxyl groups originally present in the precursor fiber. Among various samples, stabilized fibers with T-i of 150 degrees C contained the largest amount of oxygen in the fiber, resulting in the highest degree of polyaromatic inner structure after the subsequent carbonization and graphitization to show the best tensile strength and modulus. We also demonstrated that the optimal mechanical, electrical, and thermal properties of the resulting graphite fiber were comparable to those of commercially available fiber products (XN-80-60s), indicating that T-i should be carefully considered to enhance the properties of carbon and graphite fibers. (C) 2020 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.

Automated summary

The study investigated the effect of controlling the initial temperature of the stabilization process on the mechanical properties of carbon/graphite fibers. It was found that fibers stabilized at 150 degrees Celsius contained the highest amount of oxygen, resulting in the best tensile strength and modulus. Changes in Ti during thermostabilization controlled the distribution of oxygen in the fibers and preserved hydroxyl groups in the precursor fibers.