Narongrith Sombatsompop, Ekkachai Wimolmala and Thirasuk Markpin

pp. 1377 - 1391

Abstract

The research involved property development of NR/SBR blend filled fly ash particles used for reinforcement in comparison with commercial silica. The effects of silica content and surface treatment by Si69 silane coupling agent were studied. The experimental results suggested that as the silica content from fly ash particles increased the cure time decreased. The increase in silica content in fly ash resulted in increases in tensile modulus, hardness, tears strength and percent compression set, but led to decreases in elongation
at break, abrasion, percent resilience and tensile strength. When adding the silane coupling agent the cure time and overall mechanical properties were improved. After thermal ageing, the tensile modulus and tensile
strength increased, but the elongation at break decreased. Overall results recommended that 20 phr of silica in 2% Si69-treated fly ash particles gave the optimum mechanical properties of the blend and can be used to
replace the commercial silica.

Keywords

• natural rubber
• SBR rubber
• fly ash
• surface treatment
• silane coupling agent
• thermal aging