3 - High-performance pitch-based carbon fibers

Abstract

High-performance pitch-based carbon fiber fulfills a small but nevertheless important role in the broader carbon fiber landscape. This chapter starts with a general introduction to pitch as a precursor material for carbon fiber, covering both natural coal tar and petroleum pitch as well as pitch from synthetic sources. This is followed by a detailed discussion on the formation of mesophase, a critical step in the production of high-performance carbon fiber. The section on the manufacturing process includes spinning of the precursor fibers, stabilization, carbonization, graphitization, and surface treatment. While pitch-based carbon fiber can be made with a range of properties, it is the high modulus, high thermal conductivity, low electrical resistivity, and low negative coefficient of thermal expansion grades that distinguish it from polyacrylonitrile-based carbon fiber. The effect of heat treatment on these properties and the relationship to structural parameters such as crystallite dimensions and orientation are described in detail in the section on structure and properties. A final section deals with applications of high-performance pitch-based carbon fibers.