Influence of particle grade on the electrical conductivity and gas-tightness of graphite/polymer composite

Graphite/polymer composites were fabricated by compression molding. Electrical conductivity and gas-tightness of composites with different grade of graphite particle were compared. The results show that particle grade of graphite has important effect on the electrical conductivity and gas-tightness of the composites. Graphite particle grade and volume fraction are important factors affecting the electrical conductivity and gas-tightness of composites. When 150 mesh graphite mixed with 50 mesh graphite, the electrical conductivity of composite increased until the volume fraction of 150 mesh graphite reached 0.05 and then decreased. However, the electrical conductivity of composite showd a monotonic increasing with the addition of 325 mesh graphite. The addition of 150 mesh and 325 mesh graphite improved the gas tightness of composite. The permeability of composite was the lowest when the volume fraction was 0.01.