采用氯化-脱氯化法制备通用级碳纤维是煤液化残渣的高附加值利用路径之一,然而迄今为止,针对以氯苯为氯源诱导的氯化-脱氯化反应的研究尚不够深入,尤其是氯苯添加量对碳纤维结构与性能的影响仍缺乏研究。以煤液化残渣为原料,以氯苯为氯源,采用氯化-脱氯化法制备通用级碳纤维。借助元素分析仪、傅立叶变换红外光谱仪、13C固态核磁共振波谱仪、X射线光电子能谱仪、基质辅助激光解吸飞行时间质谱仪、扫描电子显微镜、拉伸强度测试仪及高精度显微镜表征研究氯苯添加量(10g~40g)对沥青前驱体分子组成与结构、熔融纺丝性及碳纤维强度性能的影响及规律。结果表明:经氯化-脱氯化法制得的煤液化残渣基沥青前驱体以芳香碳为主要组成,碳元素含量达91%以上,且碳元素含量和碳氢质量比随着氯苯添加量的升高而略微降低;X射线光电子能谱分析结果表明,经脱氯化反应后未见氯元素残留;氯化-脱氯化反应促使了芳环之间的缩聚,当氯苯添加量为20g时,平均相对分子质量的质荷比为677;通过13C固态核磁共振波谱可知,氯苯诱导的缩聚反应主要是加强了芳环的渺位缩聚,当氯苯添加量从10g增加至40g时,渺位缩聚碳的含量从9.40%提升至11.78%,这说明沥青前驱体的分子结构沿着一维方向呈现线性排列,进而熔融纺丝性随着氯苯添加量的增加而明显提高,CLR-CB-30和CLR-CB-40两组沥青前驱体在293r/min的缠丝转速下仍能实现连续纺丝而不发生断裂,碳纤维的表面和断面光滑无缺陷,平均强度性能最高达932MPa,平均直径约为12μm。表明采用氯化-脱氯化法制备出的煤液化残渣基通用级碳纤维具有较好的强度性能,达到了目前以煤焦油沥青或者石油沥青为原料工业化生产的通用级碳纤维的水平。

The preparation of general-purpose carbon fibers through chlorination-dechlo- rination method represents a high value-added utilization path for coal liquefaction residue. How- ever, the chlorination-dechlorination reaction induced by chlorobenzene as a chlorine source has not been studied in-depth so far. In particular, the effect of the amount of chlorobenzene added on the structure and mechanical performance of carbon fibers still requires further investigation. Thus, the general-purpose carbon fibers were prepared using coal liquefaction residue as raw ma- terial and chlorobenzene as a chlorine source through the chlorination-dechlorination method. El- emental analyzer, Fourier transform infrared spectroscopy,  13C solid-state nuclear magnetic reso- nance spectroscopy, X-ray photoelectron spectroscopy, matrix-assisted laser desorption/ioniza- tion time-of-flight mass spectrometer, scanning electron microscopy, tensile strength tester, and high-precision microscopy were used to reveal the effect of increasing the chlorobenzene addition amount from g to g on the composition, structure, and spinnability of pitch precursors, as well as the mechanical performance of carbon fibers. The results show that the pitch precursor derived from coal liquefaction residue prepared by the chlorination-dechlorination method is main- ly composed of aromatic carbon, and the content of carbon element exceeds 91%. The carbon content and carbon and hydrogen mass ratio slightly decrease with the increase in the chloroben- zene addition amount. XPS spectra show that no residual chlorine is detected after the dechlorina- tion reaction. The chlorination-dechlorination reaction promotes the condensation between aro- matic groups. When the amount of chlorobenzene added is g, the m/e of the average relative molecular mass is 677. Moreover, it can be seen from  13C NMR analysis that the condensation re- action induced by chlorobenzene mainly improves the cata-condensation of aromatic groups. As the amount of chlorobenzene added increases from 10% to 40%, the content of cata-condensation carbon rises from 9.40% to 11.78%, indicating that the molecular structure of pitch precursors presents a linear arrangement along the one-dimensional direction. In addition, the spinnability is significantly enhanced with increased chlorobenzene addition, while CLR-CB-30 and CLR-CB-40 can still maintain continuous spinning without breakage at a winding speed of r/min. The surfaces and cross-section of carbon fiber are smooth and defect-free. The average mechanical performance of carbon fibers is up to MPa, and the diameter of them is approximately μm on average. It is well known that the coal liquefaction residue-based general-purpose carbon fiber prepared using the chlorination-dechlorination method exhibits potential mechanical performance, which reaches the level of the mechanical performance of general-purpose carbon fiber using coal tar pitch and petroleum pitch as raw materials.