Petroleum-Based Safe Process Oils in NR and NR/SBR Blends: Effects of Oil Types and Contents on the Properties of Carbon Black Filled Compounds

The influences of mineral oils: Distillate Aromatic Extract (DAE), and low Polycyclic Aromatics containing Treated Distillate Aromatic Extract (TDAE) and Mildly Extracted Solvate (MES) on the properties of carbon black reinforced Natural Rubber (NR) and NR/SBR (Styrene-Butadiene Rubber)  blend compounds are discussed. The properties are strongly affected by oil contents, but relatively little by the oil types. Compounds with DAE have the lowest Mooney viscosity but highest complex viscosity and Payne effect. Scanning Electron micrographs show that the carbon black is finely dispersed in the compounds, except for MES which shows slightly poorer filler dispersion than TDAE and DAE. The use of TDAE and MES in NR clearly influences the properties related to changes in the Glass Transition Temperature (Tg) and viscoelastic behavior. Apart from minor solubility differences, the differences in the Tg’s of the various oil types are the major factors influencing their performance. Use of MES gives the best elastic response in NR, while TDAE gives the best response for NR/SBR blend vulcanizates.