Direct preparation of mesophase pitch from naphthalene by the aid of HF/BF3.

Direct preparation of mesophase pitch from naphthalene was studied using HF/BF3 in an autoclave under autogeneous pressure at 260 °C. A mesophase pitch of 100% anisotropy was produced catalytically first at a yield above 60%. The pitch carried 52% of benzene soluble fraction, exhibiting softening temperature of as low as 215 °C. The pitch consisted principally of naphthalene oligomers which carried a large content of naphthenic hydrogens with some alkyl and phenyl groups. The pitch was smoothly spun into thin fiber, which was rapidly stabilized for 30 min at 270 °C.