Impact of P-Tert-Butylphenol on the Oxidation Stabilization Characteristics of Pitch-Based Carbon Fibers

A novel method for enhancing oxidative stabilization through the addition of p-tert-butylphenol (TOH) to the as-prepared pitching process was developed. TOH can be used as a radical initiator to quickly and uniformly stabilize the pitch. The properties of spinnable pitches, the effects of oxidation stabilization, and the polymerization mechanism were thoroughly elucidated. The findings revealed that the introduction of TOH led to an increase in the fraction of aliphatic structures as well as the oxygen content within the pitches. This increase facilitated the formation of oxygen-containing groups and promoted crosslinking reactions among the pitch molecules. Notably, the hydrogen in the OH group of TOH displays high reactivity, readily engaging in cross-linking reactions with the benzyl radicals in halogenated polycyclic aromatic hydrocarbons (PAHs-X) during heat treatment. Consequently, an ether bond is formed between the benzyl radical in PAHs-X and the hydroxyl radical in TOH. High temperatures could expedite the formation of aryl ester functional groups in an inert gas atmosphere and hasten the crosslinking of PAHs molecules, resulting in the formation of a macromolecular structure with a certain degree of polymerization. This modification method is expected to provide a new approach for expediting oxidative stabilization.