Assessment the performance of chemical constituents of agro wastes in production safety alternative carbon black filler in rubber composite purpose

Recently, minimizing petroleum resources as well as safely disposing of agro-wastes are essential for the production process to comply with environmental legislation. Bio-filler as an alternative to non-safety carbon black (CB) from petroleum resources in the production of rubber composites is investigated by many researchers, but unfortunately it leads to deterioration of the properties of rubber composites. To avoid this drawback, different agro-wastes (rice straw, date palm fiber, and reed (Arundo donax L.) with different chemical constituents as precursors of biofillers (biochars) are assessed toward the performance of ethylene-propylene-diene terpolymer rubber (EPDM). The role of replacing parts of CB with biochar on the rheological characteristics, physico-mechanical properties, hardness, swelling, and crosslinking density of EPDM composites is studied. The results proved the efficient low replacing ratio of biochar towards increasing the minimum and maximum torque; this indicates a homogeneous filler structure and crosslinking interactions between the components matrix as emphasized from the morphological analysis of EPDM rubber. The reverse trend is noticed on increasing the replacement ratio over 25%, where it deteriorates the tensile strength in comparison to pristine CB. The data demonstrated the most efficient biochar, which is derived from RS. The formulation containing 75% CB and 25% RS-biochar provided EPDM with tensile strength (14.4 MPa), higher than the pure CB (12.45 MPa). Moreover, this optimum formulation provided high crosslinking density, high hardness shore A, and swelling resistance of motor oil and toluene when compared to EPDM with pure carbon black. This promising finding trend is not noticed in the literature on using biochars, which usually caused the deterioration in properties of rubber products.