Isotropic pitch-based carbon fiber was successfully prepared from tetrahydrofuran-soluble fraction of coal tar pitch cocarbonization with petrolatum by air-blowing. The effects of reaction temperature and time, amount of petrolatum added on the composition and spinning properties of resultant pitches were investigated. It indicated that petrolatum could effectively improve the softening point, aromaticity, hydrogen content and molecular weight of the resultant pitches by promoting cross-linking and dehydrogenation polymerization reactions at low air-blowing temperature. Moreover, more aliphatic and naphthenic structures had been introduced into resultant pitches as addition of petrolatum and also inhibited the generation of quinoline-insoluble particles. The obtained green fibers were facile to be stabilized and carbonized and the resultant carbon fibers showed fully isotropic and finer, uniform diameter with smooth surface and higher tensile strength of up to 0.92 GPa. It provided a facile chemical modification method for isotropic pitch-based carbon fiber production.

Controlling spinning pitch property by tetrahydrofuran-soluble fraction of coal tar pitch co-carbonization with petrolatum
    Abstract
    Graphical abstract
    1 Introduction
    2 Experimental section
        2.1 Materials
        2.2 Preparation of pitch precursors and pitch-based carbon fibers
        2.3 Characterization of pitch precursors and carbon fibers
    3 Results and discussion
        3.1 Properties of the CTP-THFS and resultant pitches
        3.2 Structural analysis of the CTP-THFS and resultant pitches
        3.3 Melt rheology of spinnable pitches
        3.4 The mechanism of chemical reactions between the CTP-THFS and petrolatum
        3.5 Preparation, stabilization and carbonization of pitch fibers
        3.6 Morphology and tensile strength
    4 Conclusions
    Acknowledgements 
    References

• Wei Jiang(State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences/University of Chinese Academy of Sciences)
• Guosong Ni(State Key Laboratory of Coal Conversion, Institute of Coal Chemistry, Chinese Academy of Sciences)
• Pingping Zuo(State Key Laboratory of Coal Conversion, Institute of Coal Chemistry)
• Shijie Qu(State Key Laboratory of Coal Conversion, Institute of Coal Chemistry)
• Yunmei Li(State Key Laboratory of Coal Conversion, Institute of Coal Chemistry)
• Hongxian Niu(State Key Laboratory of Coal Conversion, Institute of Coal Chemistry)
• Wenzhong Shen(State Key Laboratory of Coal Conversion, Institute of Coal Chemistry)