抄録
The effects of particle size and shape of graphite dispersing in low-density polyethylene(LDPE)on percolation phenomena are reviewed. Flake and spherical shaped graphite with mean particle size from 2.1 to 82.6μm are used The value of critical volume fraction of particles, φc, increases linearly when the mean particle size of the graphit flakes increase. The maximum value of φc was given when a spherical particle was used. In addition influence of the polarity of polymer matrix on the degree of dispersion of hydrophilic SnO2 and hydrophobic spherical graphite particles and percolation phenomenon of conductive particles/polymer composites is reviewed. LDPE and ethylene-vinyl acetate copolymer(EVA) that vinyl-acetate content is 7 and 15 wt% are used as polymer matrix. The φc of SnO2/polymer composites increase by co-polymerization of polar vinyl-acetate groups in nonpolar LDPE. On the other hand, the φc of graphite/polymer composites are not related to vinyl-acetate content.
