HOW CARBON FIBER IS CREATED?

Carbon fiber is a polymer of sime form of graphite. Graphite is a form of pure carbon. In graphite the carbon atoms are arranged in large sheets of hexagonal aromatic rings.

Carbon fiber is made from another polymer, called polyacrylonitrile, through a complicated heating process. When polyacrylonitrile is heated, the heat causes the cyano repeating units to form rings.

As the heat increases, the carbon atoms lose their hydrogens and the rings become aromatic. This polymer constitutes a series of fused pyridine rings.

The temperature is then increased to about 400-600Cº. In this way, adjacent strings are joined.

This heating releases hydrogen and gives  a ribbon-shaped ring-fused polymer. By further increasing the temperature from 600 to 1300Cº, new ribbons will join to form wider ribbons.

This releases nitrogen. As can be seen, the polymer that is obtained has nitrogen atoms at the ends, so

these ribbons can join to form even wider ribbons. As this occurs, more nitrogen is released. At the end of thw procces
the ribbons are extremely wide and most of the nitrogen has been released, leaving behind a structure that is almost pure carbon in its graphite form.