Carbonization Mechanism of Aromatic Hydrocarbons

As shown in Table 4.1, the graphite precursors can be divided into two major classes (a) aromatic hydrocarbons emd flj) polymers, each with different carbonization characteristics. 

Structure of Aromatic Hydrocarbons. The term hydrocarbon refers to an organic compound that contains oniy carbon and hydrogen. Aromatics are hydrocarbons characterized by the presence of at least one benzene ring. Aromatics have a graphite-like structure and graphite is often considered as the parent of all these compounds. The structure of benzene is shown below  

The structures of the aromatics listed in Table 4.1 are shown in Figs. 4.2 (coke formers) and 4.3 (char formers). Some of the most important aromatics are the following 

It carbonizesto a char in a manner similar to anthracene but with a lower yield. 

Mesophase. The general carbonization mecheinism of polyaromatic hydrocarbons is relatively simple, at least in theory, since it proceeds by the rupturing of the carbon-hydrogen bonds and the removal of the hydrogen. Some of these hydrocarbons first go through an intermediate liquid or plastic stage which occurs at temperatures above approximately 400°C. This stage is the so-called mesophase , in which the material shows the 

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