The Reinforcing Potentials of White Sand as Filler in Natural Rubber Vulcanizates

Abstract

Natural rubber with constant viscosity of 10, Standard Nigerian Rubber (SNR 1 0) was compounded with locally sourced white sand (WS) and standard silica (SS) as fillers. The WS was wet screened with a 75 µm stainless sieve and the screened sample was air -dried and pulverized for use as filler. The filler samples were characterized in terms of pH of aqueous slurry, loss on ignition, density, iodine adsorption number and moisture content. The cure characteristics, physico -mechanical and percentage swelling properties of the WS-SNR 10 in comparison with SS -SNR 10 vulcanizates were deter mined. The results showed that cure characteristics of WS -SNR 10 and SS -SNR 10 vulcanizates; scorch time, cure time and maximum torque increased as filler loading is increased. The tensile properties, tensile strength and modulus of WS- SNR 10 and SS -SNR 10 vulcanizates increased as filler loading increased to an optimum of 40 parts per hundred (phr) respectively, while elongation at break decreased as filler loading is increased. Abrasion resistance and hardness of WS -SNR 10 and SS -SNR 10 vulcanizates respe ctively increased to optimum level at 40 phr as filler loading is increased while compression set decreased as filler loading is increased. Percentage swelling in petroleum solvent is highest in gasoline, and lowest in diesel (gasoline>kerosene>diesel). The extent of reinforcement is in the order of SS -SNR 10 vulcanizates>WS- SNR 10 vulcanizates in cure characteristics, SS-SNR 10 vulcanizates>WS-SNR 10 vulcanizates in tensile- mechanical properties and SS -SNR 10 vulcanizates