ABSTRACT:The mechanical behavior and microhardness characteristics of a natural rubber vulcanizate loaded with 40 phr high abrasion furnace carbon black swollen in kerosene were studied. The measured parameters (i.e., the Young's modulus, tensile strength, and elongation at break) varied with the swelling time in kerosene. The hardness degree decreased as the swelling time in kerosene increased. Different models were applied to describe this mechanical behavior. The Mooney-Rivilin relation agreed with the experimental data at low extension ratios, whereas the Blatz relation agreed at high extension ratios only. The strain rate sensitivity was taken into account to describe this mechanical behavior. The strain energy density as a function of the swelling time in kerosene was calculated with three different equations.