Electrical and mechanical property transitions in carbon-filled poly(vinylpyrrolidone)

The effect of carbon black content on the mechanical and electrical propert ies of carbon-black-filled poly(vinylpyrrolidone) composites was determined . Experimental data show a drop in modulus when the volume of carbon black exceeds 25%, coincident with pore: formation documented by scanning electro n microscopy. This behavior is consistent with surpassing the critical pigm ent volume concentration. Electrical conductivity, however, does not show a discontinuous change in behavior at 25 vol% carbon black and continues to increase through a carbon black loading of 35 vol%. A qualitative model of microstructural evolution is presented to explain the observed differences in electrical and mechanical behavior.