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

Abstract

A novel method for enhancing oxidative stabilization through the addition of p-tert-butylphenol (TOH) to the as-prepared pitching process was developed. Spinnable pitches were successfully prepared by heat treatment in air, then in an inert gas atmosphere after the introduction of TOH. The characteristics of the as-prepared pitches, the impact of oxidation stabilization, and the polymerization mechanism were comprehensively 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 PAH-X during heat treatment. Consequently, an ether bond is formed between the benzyl radical in PAH-X and the oxyhydryl radical in TOH. High temperatures could expedite the formation of aryl ester functional groups in an inert gas atmosphere and hasten the crosslinking of PAH molecules, resulting in the formation of a macromolecular structure with a certain degree of polymerization. The addition of 15% TOH resulted in excellent mechanical properties, highlighting the efficacy of this novel method.

Keywords: p-tert-butylphenol, benzyl radicals, cross-linking, oxidation stabilization, aryl ester functional groups