In-Situ Doping B4C Nanoparticles in Mesophase Pitch for Preparing Carbon Fibers with High Thermal Conductivity by Boron Catalytic Graphitization

Yue Liu; Jiahao Liu; Jianxiao Yang; Xiao Wu; Jun Li; Kui Shi; Bo Liu; Ruixuan Tan

doi:10.3390/molecules27165132

In-Situ Doping B₄C Nanoparticles in Mesophase Pitch for Preparing Carbon Fibers with High Thermal Conductivity by Boron Catalytic Graphitization

Molecules. 2022 Aug 12;27(16):5132. doi: 10.3390/molecules27165132.

Authors

Yue Liu¹, Jiahao Liu¹, Jianxiao Yang¹, Xiao Wu¹, Jun Li², Kui Shi¹, Bo Liu³, Ruixuan Tan¹

Affiliations

¹ Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology, College of Materials Science and Engineering, Hunan University, Changsha 410082, China.
² School of Chemistry and Biological Engineering, Changsha University of Science and Technology, Changsha 410114, China.
³ Key Laboratory of Bionic Engineering, Ministry of Education, Jilin University, Changchun 130022, China.

Abstract

The boron carbide (B₄C) nanoparticles doping mesophase pitch (MP) was synthesized by the in-situ doping method with tetrahydrofuran solvent, and the corresponding MP-based carbon fibers (CFs) were successfully prepared through the melt-spinning, stabilization, carbonization and graphitization processes. The structural evolution and properties of boron-containing pitches and fibers in different processes were investigated for exploring the effect of B₄C on mechanical, electrical and thermal properties of CFs. The results showed that the B₄C was evenly dispersed in pitch fibers to provide active sites of oxygen, resulting in a homogeneous stabilization and ameliorating the split-ting microstructures of CFs. Moreover, the thermal conductivity of B1-MP-CF prepared with 1 wt.% B₄C increased to 1051 W/m•K, which was much higher than that of B0-MP-CF prepared without B₄C (659 W/m•K). While the tensile strength of B₄C-doped CFs was lower than that of pristine CFs. In addition, a linear relationship equation between the graphite microcrystallite parameter (I_D/I_G) calculated from Raman spectra and the thermal conductivity (λ) calculated according to the electrical resistivity was found, which was beneficial to understand the thermal properties of CFs. Therefore, the doping B₄C nanoparticles in MP did play a significant role in reducing the graphitization temperatures due to the boron catalytic graphitization but decreasing the mechanical properties due to the introduction of impurities.

Keywords: carbon fiber; graphitization; mesophase pitch.

Abstract

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