Preparation of Flexible Graphite Sheet with Fine Flake Graphite
Flexible graphite was prepared using the fine flake graphite that could go straight through 149-85μm mesh as raw material, using sulfate acid and nitrate acid as inserting agent and Potassium permanganate as oxidant. The best oxidation reaction conditions are as follows: VSulfate acid/VNitrate acid =5:1, m (fine graphite)/m (Potassium permanganate)=1/0.12, the limited temperature is about 1100-1200°C. Under such condition, the expansion volume of the fine flake graphite with 250-149μm can be reached to 341ml/g. The graphite with 149-85μm can be reached to 230ml/g, the qualities of flexible graphite sheet when intensity is 1.20 g/cm3 are as follows: tensile strength is 4.09 Mpa; ash ratio is 2.19%; recovery rate is 7.8%; compression ratio is 44.0%, TG at 450°C is 0.32%; TG at 600°C is 18.97%; Stress relaxation rate is 3.1%.
Liangchi Zhang, Chunliang Zhang and Zichen Chen
Q. Lai "Preparation of Flexible Graphite Sheet with Fine Flake Graphite", Advanced Materials Research, Vols. 328-330, pp. 1642-1645, 2011