Nanostructured Silica From Bagasse Ash: The Importance of Mixing Parameters on its Reinforcing Role in Natural Rubber Composite

Abstract

This study analyzes the effects of rotor speed, mixing time, and initial temperature on the curing characteristic, mechanical and dynamical properties, as well as the morphology of nanostructured silica/natural rubber composites. The rotor speed, mixing time, and initial temperature settings of the mixer were adjusted in the range of 40–100 rpm, 15–24 min, and 80–100 °C, respectively. Furthermore, a combination of good dispersion with a moderate mastication effect was used to obtain the vulcanizate's good mechanical properties and prevent premature crosslinking. The result showed that at a rotor speed of 60 rpm, excessive rubber degradation occurred at the compounding time of more than 21 min, while at the compounding time of 24 min, it occurred at rotor speeds of more than 40 rpm. Meanwhile, premature crosslinking occurred at an initial mixing temperature of 100 °C, with a velocity gradient in the range of 8.2–11.3 s−1 providing excellent reinforcement of natural rubber composite by nanostructured silica from bagasse ash.