Pyrolyzed, conducting kapton polyimide: An electrically conducting material

Polyimide was pyrolyzed in an argon atmosphere at 900°C for 1h. The room temperature conductivity of the polyimide gradually increased from 15 to 100 S/cm with increased pyrolysis time. Further increase in the pyrolysis time did not increase the conductivity. X‐ray photo‐electron spectroscopy (XPS) showed that the polyimide changed from pure insulator to conductor; detailed XPS spectra of carbon, nitrogen, and oxygen 1s bands showed no further elemental decomposition of the polyimide at 900°C. The high temperature treatment results in internal rearrangement to form a large, dense heterocyclic network. The film probably consists of tiny conductive particles dispersed in an amorphous carbon matrix. The polyimide is placed between two quartz plates during pyrolysis; the resulting film is flat, has uniform conductivity, is nonbrittle, has high chemical resistance, and shows better mechanical strength than films pyrolyzed in free‐standing conditions.