Carbonization of cellulose fibers—I. Low temperature pyrolysis

The pyrolysis of cellulose up to 500°C has been studied primarily by the use of infrared absorption techniques on fibers and films in various stages of degradation. Combining these results with those obtained from static thermogravimetric analysis, gas evolution data, and physical property data has permitted detailed reaction mechanisms for the carbonization process to be postulated. The process is described in terms of four successive stages: 1, desorption of physically adsorbed water; 2, splitting off of structure water; 3, chain scissions, or depolymerization, and breaking of C—O and C—C bonds within ring units, accompanied by evolution of more water, CO, and CO2, and 4, aromatization, or formation of graphite-like layers. The ultimate residue from each cellulose ring unit is postulated to be four-carbon atoms which serve as the basic building block for the formation of graphite layers.