Use of Coir-Filled LLDPE as a Reinforcement for Natural Rubber Composite

Cellulose based fibers such as sisal, jute and coir are ones of the most frequently used reinforcing fillers for composite materials including natural rubber composites because they can improve mechanical properties of their composites. However, the main disadvantages of these composites are the poor compatibility between the fiber surface and the host matrices, mainly due to the highly hydrophilic character of the fibers and the hydrophobic character of the host materials. Therefore, in this research, coir had been modified with linear low-density polyethylene (LLDPE) prior to introducing into the natural rubber composites. The coir-filled LLDPE was synthesized by in situ polymerization with MAO/metallocene catalyst, named as modified coir. The unmodified coir and modified coir were then blended with natural rubber latex to obtain natural rubber composites. The morphology and thermal dynamic mechanical properties of the composites were investigated by scanning electron microscopy (SEM), and dynamic mechanical analysis (DMA). The composites blended with the modified coir showed the better compatibility between the coir and the natural rubber than those with the unmodified coir. In addition, they also showed the greater storage modulus and lower tan delta than the unmodified counterpart and the pure natural rubber without the reinforcement.