ABSTRACT
The main objective of the present study was to investigate the synergistic effect of simultaneous use of two reinforcing fillers in rubber compounds based on NBR. Silica was used as reinforcing filler in all samples and the loading content was 25 phr. 3 phr of nanoclay, carbon nanotube and whiskers was used as second reinforcing filler in NBR/silica compounds. Melt mixing method was employed for compound preparation. The effects of nanoclay/silica, carbon nanotube/silica and whiskers/silica on mechanical and vulcanization characteristics of the rubber compounds were investigated. Vulcanization characteristics of compounds were determined by Monsanto Oscillating Disk Rheometer 100 at 150 ˚C. These results indicate that the presence of two reinforcing fillers greatly reduces the curing time and increasing the curing rate of compounds. A significant increase of the rubbery modulus was obtained upon filler addition. The reinforcing effect was particularly important for the compounds reinforced with 25 phr silica and 3 phr nanoclay and whiskers. However, this situation was not valid for carbon nanotube containing samples. Formation of nanoclay-silica, whiskers-silica and carbon nanotube-silica subassembly should be responsible for this synergism effect.
