Enhanced percolative properties from partial solubility dispersion of filler phase in conducting polymer composites (CPCs)

A variant of the standard solubility parameter concept was applied in the development of a partial-solution mixing model for this work. When correlated to polymer swelling ratios, it served as a useful tool for process control and percolation development. Polymer compositions of poly(acrylonitrile butadiene styrene) and poly(styrene butadiene styrene) block copolymers, in powder form, were classified into narrow particle size ranges and controllably coated with graphite filler in a solvent of defined solubility parameter. A percolation concentration of 0.23 vol.% was achieved for partial-solution mixing, which was a decade lower than that for a conventional solution mixing process. Further, the mean resistivity and standard deviation were much less for the classified than for a broad particle size range, by factors of ∼14 and ∼3, respectively. Compressive yield strength, used as a measure of composite cohesion, was 32 MPa, about 25–60% higher than for dry, wet or solution mixing. The application of solubility parameter as a control aid in partial-solution mixing (PSM) was found also to be an effective tool in control of electrical percolation.