A study of film thickness dependence of the graphitizability of PMDA–ODA polyimide-derived carbon film

Abstract PMDA–ODA (pyromellitic dianhydride–4,4′-oxydianiline) polyimide (PI) films with thickness of 2–26 μm were synthesized and heat-treated at 2200–2500°C. The effect of film thickness on both the graphitizability of the PI-derived carbon film and the crystalline organization of the initial PI film was investigated by X-ray diffraction. The degree of graphitization of the resultant carbon film was observed to increase with decreasing initial PI film thickness, corresponding to the film thickness dependence of the crystalline ordering in the initial PI films. Structural factors related to PI film thickness are discussed for understanding the graphitizability of the resultant carbon.