2.1.2. Rubber Compound Fabrication

The NR compounds both with and without nanosilica were fabricated following the formulations given in Table 1. Initially, the NR, ZnO, stearic acid, paraffin, and nanosilica were put into an internal mixer (Brabender Plasti-corder 350s, Brabender GmbH & Co. KG, Berlin, Germany) at different compositions depending on the sample number and mixed well at 50 ◦C with a rotor speed of 50 rpm for 1 h [42]. Further mixing was accomplished with a two-roll mill once three vulcanizing accelerator chemicals and sulfur were added. The rubber compounds were either used for examining curing characteristics or vulcanized to determine their mechanical properties.


**Table 1.** The composition of silica/natural rubber compounds.
