Pyrolysis Mechanism of Composite Binder Composed of Coal Tar Pitch and Phenolic Resin for Carbon Materials

The composite binder consisting of coal tar pitch (CTP) and phenolic resin (PR) has both low viscosity and high char yield, and it has great potential in the preparation of advanced carbon materials. However, the lack of understanding of its synergetic behavior and mechanism hinders the optimization of the preparation process. In this work, the co-pyrolysis of CTP and PR was systematically investigated. The char yield of the composite binder was confirmed to be remarkably higher than the weighted average of the two single binders. Furthermore, the calculated activation energy for the pyrolysis of the composite binder was higher than that of CTP and PR after 400 degrees C. The interaction and structure evolution mechanisms of composite binder were clarified. Specifically, the ortho-position of the phenoxy carbon in CTP cross-link with the para-position of the phenoxy carbon in PR by the methylene bridge, and the free polycyclic aromatic hydrocarbons stack onto the as-crosslinked polycyclic aro-matics driven by the pancake bonds.