This work studies possibilities of using bagasse fiber ash (BFA) as alternative and/or secondary filler in
natural rubber (NR) compounds containing either precipitated silica (PSi) or carbon black (CB) as the primary
filler. The effects of the filler content and weight fraction ratio of BFA in PSi and CB fillers on cure
characteristics, and mechanical properties were of interest. The studies reveal that silicon dioxide (SiO2)
was the major component of BFA with 75.4% by weight and the rest was metal oxides. The BFA particles
showed porosities and shape irregularities with a particle size range of 45–150 lm. For the neat filler system,
it was found that the BFA filler could be used potentially as alternative filler in NR compounds with a
recommended loading of not greater than 15 parts per hundred rubber. Lower tensile strength of the vulcanizate
with BFA filler, as compared to PSi and CB filler, was due to the poor dispersion level and an
aggregation of the silica particles in the rubber matrix. In the hybrid filler system, BFA could be used
to replace both PSi or CB filler up to 75% of the total hybrid filler (either BFA:PSi or BFA:CB) not exceeding
15 phr, without affecting the ultimate mechanical properties. The results of ultimate mechanical strength
and swelling measurements clearly indicated that the BFA filler had more compatibility for addition with
PSi filler than CB.