Cure Characteristics and Mechanical Properties of Carboxylated Nitrile Butadiene Rubber (XNBR) Vulcanizate Reinforced by Organic Filler

Carboxylated nitrile rubber (XNBR) composite containing organic filler was fabricated on lab-scale, two-roll mill. The organic filler originated from the olive husk powder (OHP). The work has two aims. The first is the role of the OHP as a co-curing agent for XNBR vulcanizate based on the fact that it is a nitrogen-containing material; the second is the potential of the OHP as reinforcing filler. Therefore, the prepared samples were inspected with reference to their cure characteristics and mechanical properties. It has been found that the OHP was able to shorten the optimum cure time (t(90)) and enhance the state of cure (difference between the maximum torque M-H and the minimum torque M-L). It was noticed that the OHP addition has increased the minimum torque (M-L), which is an indirect indication of increased viscosity of the vulcanizate. The cure behavior change was accompanied with a notable improvement in the mechanical properties of the composites as compared to the pristine counterpart. Attenuated total reflectance infrared spectroscopy (ATR-IR) was used to explore the possibility of any interactions between the filler and the matrix. Dynamic mechanical analysis (DMA) was carried out on the fabricated composites. The related parameters, such as the mechanical loss factor (tan delta and storage modulus (E), were reported.