Carbonization Behavior and Graphitization of Organic Precursor Films Reported to Give Graphite

Four organic polymer films, Novax, Kapton, PPV and POD, which have been reported to give well-crystallized graphite, were compared in their carbonization behavior followedby the changes in weight, size, chemical composition and pyrolyzed gas composition. Also their graphitizability was characterized by magnetoresistance.Polyimide films, Novax and Kapton, released their non-carbon atoms in two steps, as CO around 600°C and as N2 above 800°C, POD film did also in two steps, but in different composition, N2 and CO around 500°C and N2 above 800°C. The carbon yield of the polyimide films was very high, particularly in Kapton.All of carbon films derived from these polymer films gave high values of magnetoresistance, that is, high degree of graphitization, after the heat treatment at 3000°C, particularly the one from Novax. During graphitization process, all films were elongated along their film surfaces, the one from PPV showing remarkable elongation.