One-step preparation of spinnable naphthyl mesophase pitch by using AlCl3 as catalyst

Mesophase pitch can serve as excellent precursor for high-performance carbon materials. The catalytic refinement of mesophase pitch and the formation mechanism are of significance. In this work, mesophase pitches with varying degrees of polycondensation were successfully produced via one-step polycondensation by employing purified naphthalene as feed and AlCl₃ as catalyst. Through analysis of the structural composition, functional group and crystal structure variations of the pitches at different stages, it was ascertained that properly elongation of polymerization time at 260 °C was favorable for the formation of mesophase pitch with flow-domain optical texture. Moreover, the principal reaction types of the system under different reaction conditions were investigated by analyzing the carbon atom configuration, molecular weight distribution and gas molecules produced from pyrolysis of the pitches. The evaluation of spinning characteristics confirmed that the mesophase pitch synthesized using this method showed improved fluidity at lower temperatures. This study enhances the liquid-phase carbonization theory and introduces a unique and practicable approach for the synthesis of pitch-derived carbon material precursors.