The effects of filler contents and particle sizes on properties of green kenaf-filled natural rubber latex foam

The effects of filler loading and size of kenaf fibre on the mechanical properties of kenaf fibre-filled natural rubber latex foam (NRLF) have been studied. The NRLF was prepared by using the Dunlop method. The kenaf fibre was sieved to 97, 144 and 200 µm particle sizes and incorporated into the rubber vulcanizates at 0, 1, 3, 5 and 7 part per hundred rubber fibre contents. Increasing kenaf fibre loading in NRLF resulted in the reduction of tensile strength, elongation at break and recovery percentage but increased in modulus at 100% (M100), compression strength, compression set, hardness and foam density. At the same kenaf fibre loading, smaller size of kenaf fibre-filled NRLF showed higher tensile properties, compression strength, compression set and hardness. Scanning electron microscope demonstrated that as kenaf fibre loading and size increased, a larger pore size of NRLF was formed and this led to tensile strength, M100, compression strength and hardness.