MECHANICAL AND THERMAL PROPERTIES OF NATURAL RUBBER REINFORCED BY ORGANOALKOXYSILANE-MODIFIED SILICA

Abstract

This research studied the surface modification of silica particles that prepared via a sol-gel process by organoalkoxysilane as modify agents such as MpTMS, PhTMS, PhTES and ATMS. The optimum condition to modify the surface of silica particles was the use of mole ratio of modify agents to TEOS of 0.4 at ambient temperature for 24 h. The characterizations of modified silica particles by fourier transform infrared spectroscopy (FTIR), hydrophobic properties by water contact angle measurement and determination of antioxidant activity by using 2, 2-diphenyl-1-picrylhydrazyl (DPPH) solution were carried out. The effects of modified silica particles on the mechanical, thermal properties and ozone resistance of natural rubber (NR) vulcanizates both the concentrated latex and solid rubber were also investigated. The good compatibility between modified silica particles and NR matrix was observed, resulting in the improvement of mechanical properties. In addition, the initial temperature of decomposition of NR vulcanizates filled with modified silica particles was highly and the modified silica particles could retard the ozone-induced degradation compared with NR vulcanizares filled with unmodified silica particles. Therefore, the modified silica particles played the role as either reinforcing filler or antidegradant for NR product.