Vulcanization characteristics and mechanical properties of natural rubber-scrap rubber compositions filled with leather particles

Scrap rubber recycling combined with waste leather particles in natural rubber compounds has been studied. The effect of leather and scrap rubber loading on vulcanization characteristics of natural rubber compounds has been evaluated. The presence of leather was found to reduce the scorch time and increase the maximum and minimum torque. While reversion was not observed in the absence of leather at 150 °C, it was more prominent when leather was incorporated. Mechanical properties such as tensile strength, elongation at break, tear strength, modulus and hardness were found to increase on increasing the scrap rubber loading in the absence of leather. Compounds containing leather exhibited higher tensile strength, modulus, hardness and tear strength values but the modulus and hardness values were found to decrease as the scrap rubber loading increased. All the vulcanizates exhibited only limited swelling in different media as the swelling of one phase of the composite was found to be restricted by the other phase. Copyright © 2004 Society of Chemical Industry