The Effects on Cure Characteristics, Physico-Mechanical Properties and Morphology of Bamboo Activated Carbon Filled Styrene Butadiene Rubber (SBR) Vulcanizates

Abstract

The role of activated carbon (AC) in rubber compounds was investigated to better understand the reinforcing mechanism. The activated carbon filled styrene butadiene rubber vulcanizates (SBR-AC) using bamboo activated carbon as filler were prepared by using two-roll mill and cured at 160 °C. AC filler loading from 10 to 50 phr (part per hundred rubber) were used in this study. Study into the influences of filler loading on the cure characteristics, swelling behavior, physical properties (hardness and resilience), mechanical properties (tensile properties) and morphology of SBR-AC vulcanizates were carried out. It was observed that SBR-AC vulcanizates has better cure characteristics compared to the styrene butadiene rubber gum vulcanizate (SBR-GV) which is a non-filled vulcanizate. The results showed that the scorch time (ts2) decreased with increasing filler loading. The cure time (tc90) slightly decreased up to 20 phr before a rise as the filler loading increased. The minimum torque (ML) of SBR vulcanizate increased and the maximum torque (MH) decreased up to 20 phr but then increased with increasing filler loading. The cure rate index (CRI) of SBR-GV vulcanizate was higher than that of all SBR-AC vulcanizates. Up to 20 phr of filler loading, the CRI increased before a decline occurred as the filler loading increased. As expected, the hardness value of SBR-AC vulcanizates was higher compared to SBR-GV vulcanizate which has lower resilience. The hardness and crosslink density showed an increasing trend meanwhile the resilience was adversely affected by the increase in filler loading. The tensile properties of SBR-AC vulcanizates also showed improvement in which the tensile strength and modulus at 100% elongation (M100) increased with increasing filler content. It has been proved in morphology study of the tensile fracture surfaces. Bamboo activated carbon showed some potential enhancement on the reinforcing and physical properties as well as mechanical properties of the vulcanizates.