Scientific publications

The effect of shungite fillers (SF), produced by grinding shungite rocks that contain 98 to 2,5% carbon, on the physicomechanical and electrophysical properties of polypropylene (PP)-based compositions. Using atomic power microscopy (APM), structural changes that occur on a submicron scale in
the matrix of PP were assessed. It has been found that the modulus of elasticity is related to the flowability limit of the compositions, and the electrophysical parameters of PP-SF
compositions are related to changes in the structural pattern of the polymer matrix (the sizes of spherulites, the extent of crystallinity) that occur with a change in the bulk share of SF. For
example, as SF content increased to ca. 40 vol.%, the modulus of elasticity rose 3–4 times and specific electrical conductivity by 5–15 orders of magnitude, the extent of crystallinity being observed to rise by 15–20% and the size of spherulites to diminish from 80 to 2–10 µm. It has been shown that addition of powder-like shungites to PP helps produce electroconductive compositions with specific electrical conductivity values σdc of up to ~10–2 (ohm · cm)–1 and increase the adhesion of PP-SF compositions to external substrates. The values of the above indices depend on the type of SF added.