Formation of Mesophase Pitches from Polycyclic Aromatic Hydrocarbons: Naphthalene and Anthracene

Abstract

Mesophase pitches derived from naphthalene and anthracene were prepared in the presence of a Lewis acid, AlCl₃, with varying the reaction conditions. The C/H ratio of naphthalene pitches increased with an increase in temperature and naphthenic groups were introduced into pitches in the early stages of the reaction. At rather severe conditions, alkyl groups were introduced. The film formed from naphthalene showed unidirectional orientation. On the basis of the experimental results, the reaction mechanisms foi the condensation of the naphthalene were proposed as cationic polymerization in the earlier stage and radical polymerization in the later stage.