Preparation of mesophase pitch with domain textures by molecular regulation of ethylene tar pitch for boosting the performance of its carbon materials

Abstract

The fast formation of mosaic optical textures is one of main factors limited its application in high performance carbon materials due to active components containing olefins in ethylene tar pitch (ETP). In this paper, a thermal pretreatment process is proposed for effective molecular reformation of ETP, especially for separation of these active components containing olefins. Mesophase pitch with developed rheological properties and domain anisotropic textures was then prepared via polymerization of the post-treated ETP. Molecular structures analysis results show that these active components containing olefins in ETP prefer to form macromolecules consisted of multiple aromatic cores via rapid radical reactions, and develop a mixed anisotropic texture consequently. Nevertheless, these normal aromatic components tend to produce a semi-rigid molecular structure with less aromatic cores by aliphatic chains transfer reactions and stable radical polymerization reactions. This architecture facilitates its molecular stacking and orientation thus the prepared mesophase pitch (ETP-MP) shows better anisotropic domain texture. The prepared mesophase pitch had suitable performance for the application in needle cokes and carbon foams. This work will help to expand the manufacturing of ETP-derived carbon materials through molecular reformation.