Influence of carbon black and cotton fiber on the mechanical and thermal properties of natural rubber composites: a statistical optimization using Central composite design

Abstract

The objective of this study is to enhance the thermal as well as the mechanical properties of vulcanized natural rubber with hybrid reinforcement including alkali-treated cotton fiber and carbon black. The central composite design and response surface methodology techniques were employed to design the experiment and examine optimum mechanical strength with corresponding optimum reinforcement composition. The tensile strength of composites increased from 1.71 to 18.87 MPa as a result of reinforcement. Likewise, the tear strength was improved from 23.20 to 57.91 N/mm. The thermal stability of the composites gets enhanced with the addition of carbon black from 320 °C to 343 °C. FTIR and SEM analysis revealed intercomponent interactions and surface texture of prepared composites. The hybrid reinforcement of cotton fiber and carbon black in the rubber matrix brings out enhancement in mechanical properties as well as the thermal stability of the final composite material. A minute increment in the density of samples was noticed with the addition of cotton fiber and carbon black in the rubber matrix. This increase in density is significantly less than the increase in mechanical strength of composites, which is a good parameter for application purposes of composites.