High-quality and highly oriented graphite block from polycondensation polymer films

Abstract High-quality and highly oriented graphite was produced in the form of a thick block having physical properties close to those of single-crystal graphite. It was prepared from polyimide films of 25 μm thick with high molecular orientation. A sheaf of the films was heat treated in an argon atmosphere at temperatures up to 1000°C (carbonization) and then heated for graphitization up to 3000°C under a pressure between 100 and 300 kg/cm 2 . Graphite blocks as large as 150 × 50 × 13 mm 3 were prepared, and the mosaic spread (the degree of preferred orientation) attained was 0.4°.