煤沥青与煤液化沥青共缩聚制备碳纤维研究OA

Mesophase pitch⁃based carbon fibers exhibit excellent performance,yet their preparation process is rela⁃tively complex,and the mechanical properties(tensile strength and tensile modulus)of carbon fibers are closely re⁃lated to the composition and structure of their precursors.Based on the high hydrogen content of coal liquefaction pitch,spinnable mesophase pitch was prepared via a one⁃step polycondensation reaction using coal tar pitch and coal liquefaction pitch as raw materials,and carbon fibers were further spun from the prepared mesophase pitch.The me⁃sophase pitch and carbon fibers were characterized by softening point tester,Raman spectroscopy,X⁃ray diffraction(XRD),scanning electron microscopy(SEM)and other characterization methods to investigate the relationships a⁃mong raw material composition,mesophase formation and the mechanical properties of carbon fibers.The results show that with the increase of coal liquefaction pitch content,the quinoline⁃insoluble(QI)content and softening point of the condensed pitch gradually rise,indicating that the addition of liquefaction pitch promotes the condensa⁃tion process.The mesophase content,structural ordering,spinnability,and mechanical properties of the condensed pitch initially increase and then decrease as the amount of liquefaction pitch increases.A small amount of liquefaction pitch facilitates the formation of well⁃developed domain⁃type mesophase with favorable spinnability.However,exces⁃sive addition accelerates the condensation process,leading to incomplete coalescence of mesophase spheres.This re⁃sults in a reduction in mesophase content and structural ordering,causing split cross⁃sections in the resulting carbon fibers and a consequent decline in mechanical performance.When the addition of coal liquefaction pitch was 5％,the prepared mesophase pitch has the optimal spinnability,with continuous spinning length of 974.3 m,the tensile strength and tensile modulus of carbon fiber are 1.38 GPa and 580.6 GPa,respectively.