RHEOLOGICAL BEHAVIOR AND MECHANICAL PROPERTIES OF RUBBER COMPOSITES BASED ON NATURAL RUBBER LOADED WITH MINERAL OILS AND PYROLYTIC CARBON BLACK

This paper aims to investigate the effect of the addition of mineral oil and pyrolytic carbon black on crosslinking the natural rubber and the mechanical properties of the crosslinked products. A rheometer determined curing characteristics at a temperature of 150 °C. The mechanical properties of prepared vulcanized composites were determined. By adding mineral oil to rubber compounds, the vulcanization reaction starts later, and it takes slightly more time to achieve the optimal vulcanization time. The addition of mineral oil to the rubber mixture achieves better dispersion of pyrolytic carbon blacks in the matrix and thus increases the physical interaction between the filler and rubber. Pyrolytic carbon black (pCB) is obtained by recycling waste products and contains a higher proportion of impurities. Due to impurities, PCB has a smaller surface area for the physical adsorption of rubber molecules than standard carbon black, and it can be assumed that this has led to a decrease in the crosslinking density. The addition of mineral oil to rubber compounds results in a slight reduction in mechanical properties. The type of carbon black has a much more significant influence on the mechanical properties of vulcanized composites based on natural rubber.