Abstract The high modulus PAN-based carbon fibers (CFs) were prepared using the B4C-doped PAN as a precursor which was synthesized by in-situ polymerization of acrylonitrile monomer with B4C nanoparticles, and were characterized to investigate the effects of B4C nanoparticles on stabilization and carbonization behaviors of the as-spun fibers and to compare the structural properties of the B4C-doped CFs (B-CF) with the pristine CFs (P-CF). The results showed that the B-CF-1000 prepared at carbonization temperature of 1000 °C had lower tensile strength than P–CF–1000 due to the defects and disordered structures in the B-CF-1000 caused by the doped B4C, while the B-CF-3000 prepared at graphitization temperature of 3000 °C had much higher tensile modulus of 399 GPa than P–CF–3000 of 251 GPa under the effect of boron catalytic graphitization. Moreover, the skin-core structure of B-CF had significantly improved compared to P-CF, which was caused by the fact that B4C inhibited the oxidation reaction and limited the shrinkage of the fibers during stabilization so as to benefit the entry of oxygen into the fiber core. The above results indicated that the in-situ doped B4C does play a significant role in catalytic graphitization and improving microstructure of PAN-based CFs.

中文翻译：

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在 PAN 前驱体中原位掺杂 B4C 纳米粒子，用于制备硼催化石墨化高模量 PAN 基碳纤维

摘要 以丙烯腈单体与 B4C 纳米粒子原位聚合合成的 B4C 掺杂 PAN 为前驱体制备了高模量 PAN 基碳纤维 (CFs)，并对其进行表征，研究 B4C 纳米粒子对稳定性的影响。和初纺纤维的碳化行为，并比较了 B4C 掺杂的碳纤维（B-CF）与原始碳纤维（P-CF）的结构特性。结果表明，由于掺杂 B4C 导致 B-CF-1000 中的缺陷和无序结构，在 1000 °C 碳化温度下制备的 B-CF-1000 的拉伸强度低于 P-CF-1000，而在硼催化石墨化作用下，在 3000 °C 石墨化温度下制备的 B-CF-3000 的拉伸模量为 399 GPa，比 P-CF-3000 的 251 GPa 高得多。而且，与P-CF相比，B-CF的皮芯结构有明显改善，这是由于B4C抑制了氧化反应并限制了纤维在稳定过程中的收缩，从而有利于氧气进入纤维核。上述结果表明，原位掺杂的 B4C 在催化石墨化和改善 PAN 基 CF 的微观结构方面确实发挥了重要作用。