Use of Neem (<i>Azadirachta Indica</i>) Seeds as Filler in Natural Rubber Compounding

Abstract

The importation of carbon black (a petroleum product) for the reinforcement of Natural Rubber (NR) is very expensive. Therefore, the need to source alternative materials locally becomes necessary. Neem seed (NS) was evaluated as reinforcing fillers in the compounding of NR. NS were collected, cleaned, dried, milled and some part of it was carbonized at 2500C. The Carbonized Neem Seed (CNS) and Uncarbonized Neem Seed (UNS) powders were sieved using 90μm mesh size and then characterized. These were then used as fillers in varying proportions (0%, 15%, 30%, 50% and 100%) with Carbon Black (CB) for the compounding of NR. The physicomechanical properties including tensile strength, elongation at break of the vulcanizates were determined. Scanning Electron Microscopy (SEM) was also used to analyze the morphology of the blend in the vulcanizates with 100% CNS, UNS and CB. The loss on ignition for the CNS was found to be 89.5 while that of UNS was 69.8. The physicomechanical analysis carried out on the vulcanizates showed better properties for the carbonized samples than the uncarbonized ones. The 15% and 30% CNS reinforced better than 100% CB as shown in the results. The SEM result showed a better dispersion of the CB into the vulcanizate with 100% CNS and UNS.