Abstract Spinnable mesophase pitch with high pitch yield of more than 50 wt% was successfully prepared using direct bitumen coal extracted fraction through the three-step process of hydrogenation, N2 blowing heat treatment, and thin-layer evaporation. The prepared mesophase pitch was smoothly spun to the fibrous form and could be converted into mesophase pitch-based carbonized and graphitized fibers through the usual oxidative stabilization, carbonization, and graphitization. The prepared mesophase pitch based carbon fibers showed typical random transversal structures with mechanical performances, tensile strengths of 1.83 GPa and 3.00 GPa, Young’s moduli of 133 GPa and 450 GPa, and elongation properties of 1.37% and 0.68% after heat treatments at 1000 °C for 30 min and 2800 °C for 10 min, respectively. The relatively high-molecular-weight and well-developed polynuclear aromatic molecular structure of hypercoal is the likely reason for the high mesophase pitch yield. The meaning of each preparation processes, hydrogenation, N2 blowing heat treatment and thin layered evaporation, was discussed in detail. We anticipate that the success of high-yield mesophase pitch manufacturing using hypercoal as raw material will be an important key to innovatively reduce the production cost of mesophase pitch-based carbon fiber.

中文翻译：

---

使用直接煤提取部分及其衍生的中间相沥青基碳纤维制造可纺中间相沥青

摘要 采用直接沥青煤提取馏分，通过加氢、吹氮热处理、薄层蒸发三步法，成功制备了沥青产率超过50%的可纺中间相沥青。将制备的中间相沥青顺利纺成纤维状，并通过通常的氧化稳定、碳化和石墨化转化为中间相沥青基碳化和石墨化纤维。制备的中间相沥青基碳纤维表现出典型的随机横向结构，力学性能为1.83 GPa和3.00 GPa，杨氏模量133 GPa和450 GPa，1000℃热处理后伸长率分别为1.37%和0.68%分别为 30 分钟和 2800°C 10 分钟。超煤的相对高分子量和发达的多核芳族分子结构是高中间相沥青产率的可能原因。详细讨论了加氢、吹氮热处理和薄层蒸发各制备工艺的含义。我们预计，以超煤为原料的高产中间相沥青制造的成功将成为创新降低中间相沥青基碳纤维生产成本的重要关键。