氯苯添加量对通用级碳纤维结构与强度性能的影响OA北大核心CSTPCD

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 10 g to 40 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 20 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 293 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 932 MPa,and the diameter of them is approximately 12 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.