Structure and percolation properties of metal-filled film polymer composites

The dependence of the conductivity of 40, 90, and 500 μm thick films of the nickel powder-epoxy resin composition on the curing temperature was studied experimentally. The assumption made earlier by the authors that conductivity and percolation behavior of the composition are independent of the average size of primary clusters, which are formed during the first stage of the particle aggregation, was confirmed by the results of this study. Conductivity and percolation characteristics of the films are mainly dependent on internal stresses that arise in the composition during its curing and vary with temperature. The effect of the moisture condensed at the sample during the curing process on the conductivity of the composite film was investigated. It was established that curing under moist conditions essentially contributes to an increase in the conductivity of the composition studied. The mechanism of the effect of moisture on the conductivity of the composite films was discussed.