High performance of synergistic reinforced natural rubber with kewda fiber ( <i>Pandanus odoratissimus</i> ) and carbon black: thermal, morphological and statistically optimized mechanical studies

Abstract This work describes the preparation of kewda fiber and carbon black reinforced natural rubber composites by the milling process. The alkali-treated fiber is incorporated in the rubber matrix as 0, 1, 3, and 5 per hundred rubber with varying amounts of carbon black 0, 10, and 15 phr. Response surface methodology was used to examine the optimum tensile (20.83 MPa) and tear strength (56.00 N mm −1 ) along with elongation at break (2,546 %) at the corresponding composition of 1.50 phr of fiber and 8.94 phr of carbon black, which are higher than that of the neat sample, 12.71 MPa and 24.56 N mm −1 . Tensile strength was diminished from 20.83 MPa to 13.19 MPa as the fiber amount was increased beyond 1 phr up to 5 phr. Likewise, the addition of carbon black beyond 10 per hundred rubber causes a decrease in mechanical properties. Scanning electron microscopy and Fourier transform infrared spectroscopy were used to study the morphology and inter-component interactions of composites. The thermal stability of the composites was improved from 320 °C to 335 °C and the maximum weight loss occurs at a higher temperature with the addition of carbon black. Thus, the reinforcement of fiber and carbon black in the rubber matrix improved the mechanical and thermal properties of the final material.