Physico-mechanical and equilibrium swelling properties of natural rubber filled with rubber seed shell carbon

Natural rubber samples were filled with rubber seed shell carbon and the blends of carbon black (N330) and rubber seed shell carbon; and vulcanized using efficient vulcanization system. The physico-mechanical properties viz. tensile strength, modules at 100%, elongation at break, flex fatigue, hardness, compression set and abrasion resistance as well as equilibrium swelling in toluene, kerosene and diesel were measured as a function of filler loading. It was found that vulcanizate with 60 phr filler loading showed optimum tensile strength of 8.8 Mpa. Hardness increased with the increasing filler loading for all the compounds. Equilibrium swelling of the vulcanizates in the solvents decreased with the increasing filler content. The reinforcing ability of rubber seed shell carbon is inferior to HAF carbon black (N330), but its blend with carbon black is not inferior to carbon black.