Meaning
Low-temperature chemical treatment preheats polymer fibers or resin precursors in the presence of oxygen to cross-link the molecular structure and prevent melting during carbonization. In carbon fiber and anode production, oxidative stabilization converts thermoplastic materials into thermosetting materials. This step ensures the carbon precursor retains its physical shape during high-temperature thermal treatment.
Chemical Pretreatment
The process requires exposing the polymer precursor to temperatures between two hundred and three hundred degrees Celsius in air. During oxidative stabilization, oxygen atoms react with polymer chains to form ether, carbonyl, and ester linkages. This chemical modification increases the glass transition temperature of the polymer.
Polymer Modification
This molecular cross-linking makes the precursor heat-resistant so that it does not liquefy when subsequently carbonized. When raw polyacrylonitrile or pitch undergoes oxidative stabilization, the polymer chains reorganize into rigid ladder-like structures. This molecular lock preserves the fiber or particle morphology.
Without this treatment, the particles would coalesce into a single fused mass, rendering the resulting carbon useless for electrochemical applications.
Process Management
The reaction is exothermic and must be carefully monitored to avoid runaway thermal events. Airflow rates and heating ramps are precisely managed to ensure uniform oxidation. Proper execution maximizes the carbon yield of the finished product.
