The Effect of the Functionalisation of Low-Dispersion Carbon Black of the OMCARB Series by Hydrogen Peroxide on the Properties of Filled Composites

The aim of this work was to produce a new filler for polymers in which a low surface activity is combined with a high degree of structure and functionalisation of the surface, which will bring the processing properties of filled rubber mixes closer to the properties of rubber mixes with channel carbon black. The oxidation of specimens of low-dispersion, highly structured carbon black of grade OMCARB S820 was carried out using aqueous solutions of hydrogen peroxide of different concentration. Using a combination of methods, including X-ray diffraction analysis (D8 Advance diffractometer; Bruker, Germany) and transmission electron microscopy (JEM 2100 electron microscope; JEOL, Japan), we assessed the physicochemical properties and the form and the number of oxygen-containing groups (carboxyl, phenolic, lactone) on the surface of a particle of oxidised S820 in comparison with carbon black K354 (produced by the Khazar Chemical Plant, Turkmenistan) and semi-active furnace black N550 (produced by Omsktekhuglerod). The rheological characteristics (MDR 3000 vibrorheometer and MV 3000 viscometer; MonTech, Germany) and the physicomechanical characteristics (tensometer; Shimadzu, Japan) of rubber mixes filled with these blacks and of rubber compounds based on natural rubber were determined. The dynamic properties of the rubber compounds and the glass transition temperatures were determined on a DMA 242D instrument (Netzsch, Germany). Comparative data on the temperature dependence of the mechanical loss tangent (tg δ) of the rubber compounds showed that at temperatures of −60 and +60°C the greatest differences are possessed by rubber compounds with K354. At intermediate temperatures, the tg δ values for rubber compounds with the different fillers are similar. The new carbon black was advantageous with respect to the strength properties and dynamic characteristics of the rubber compounds, retaining the unique properties of composites filled with channel black.