29 Progress in Rubber, Plastics and Recycling Technology, Vol. 25, No. 1, 2009 Chemically Modified Carbon Black Filled Ethylene-Propylene-Diene Rubber Composites: Mechanical and Dynamic Mechanical Study * Corresponding Author © Smithers Rapra Technology, 2009 Chemically Modified Carbon Black Filled Ethylene- Propylene-Diene Rubber Composites: Mechanical and Dynamic Mechanical Study Sini N.K., Arup Choudhury and Gautam Sarkhel* Department of Polymer Engineering, Birla Institute of Technology, Mesra 835 215, Ranchi, India Received: 6 August 2007, Accepted: 19 March 2008 ABSTRACT A surface-modified carbon black (N330) has been prepared by treating it with pentaerythitol, combination of pentaerythitol and pyrogallol and a combination of pentaerythitol and resorcinol in aqueous solution at different molar concentrations. The adsorption of modifier and formation of new functional groups could be identified from the FTIR peaks. This modified carbon black has been used as one of the compounding ingredients in EPDM rubber. It was found that carbon black modified with pentaerythitol and resorcinol showed more pronounced effect than the other two. In all cases the properties like hardness, tensile strength, and modulus are found to be increasing as the concentration of modifier was increased. All these values are higher as compared to rubber compound with unmodified carbon black. While the properties like abrasion loss, compression set, elongation at break, tan delta were found to be decreasing with increase in modifier concentration. All these results points towards an improved interaction between the filler and rubber. The surface functional groups on the modified carbon black would attach to the rubber chains and will act as secondary cross linker. Calculated values of crosslink density were found to be increasing with the modifier concentrations, clearly defines the formation of secondary crosslinking. INTRODUCTION The most widely used filler in elastomeric substances is carbon black. The wide range of physical and chemical natures viz. particle size, surface area, structure, surface activity etc. which governs its relationship with the elastomer