EFFECT OF OXIDATION ON THE PROPERTIES OF CARBON-FIBER

Aromatization index (AI value) is a method for evaluating the degree o f oxidation in carbon fiber. As the AI value of oxidized polyacrylonit rile (PAN) fiber is about 30%, a carbon fiber with better properties c an be obtained by using a two-stage carbonizing furnace, whereas the c arbon fiber produced in a one-stage carbonizing furnace has lower mech anical properties. If PAN fiber is oxidized by a different oxidizing p rocess, the oxidized fibers with the same AI value exhibit very differ ent properties. The results show that the carbon fiber for the PAN fib er oxidized in stages from low temperature to higher temperature has s uperior properties, compared to fibers oxidized directly at a higher t emperature.