Physico-Mechanical properties of natural rubber filled with chemically modified Groundnut shells were studied. Natural rubber composites were prepared using modified fillers at varying concentrations of sodium hydroxide (NaOH) Solution and acetylating solutions respectively. The proceability conditions, mechanical properties and sorption characteristics of these composites were analyzed. The cure characteristics of the compounded rubber were determined using Mosanto Rheometer (model MDR - 2000).The maximum torque and cross-linking density increases with increasing concentrations of the mercerizing and acetylating agents. The fibre reinforcing efficiency of the chemically treated composites were compared with that of the untreated composite. Composites containing chemically treated fillers were found to posses improved tensile properties, hardness and abrasion resistance. These properties increases with increase in mercerizing and acetylating agent upto 20% concentration and starts decreasing. At higher concentration, the fibre is destroyed hence reduction in properties. These results were in agreement with empirical analysis. The sorption properties of the composite also vary with the concentration of the mercerizing and acetylating agent. The improved properties observed were as a result of the increase in affinity between the rubber matrix and the chemically treated groundnut shell fillers

Keywords: Modified, Shell, Mercerization, Acetylation, Composite, Cross-linking, Sorption, Fillers, Matrix