Exploration of the role of nanoferrite load and particle size on the rheometric, mechanical, and dielectric properties of (Co0.2Zn0.8Fe2O4/NBR) nanocomposites

Abstract

Spinel nanoferrite powder with chemical formula Co<inf>0.2</inf>Zn<inf>0.8</inf>Fe<inf>2</inf>O<inf>4</inf> was synthesized by sol–gel citrate method. Moreover, nanocomposites of (Co<inf>0.2</inf>Zn<inf>0.8</inf>Fe<inf>2</inf>O<inf>4</inf>/Nitrile butadiene rubber [NBR]) with different ferrite filler loads (2, 4, 6, 8, 10, 12, 14, 20, 25, and 30 phr) were prepared aiming to enhance more improvements of the mechanical and dielectric properties of NBR to be used in communication and data transmission applications. Different techniques (XRD, SEM, and TEM) were used to investigate the structural and morphological properties of the ferrite and (ferrite/NBR) nanocomposites. Several properties were measured: rheometric [maximum torque (M<inf>H</inf>), hardness, scorch (ts<inf>2</inf>) and cure (tc<inf>90</inf>) times, cure rate index (CRI)], mechanical [stress at yield (σ<inf>B</inf>), stress at rupture (σ<inf>R</inf>), Young's modulus (E)] and dielectric [electrical resistivity (ρ<inf>ac</inf>), real (ε′), and imaginary (ε″) parts of the dielectric constant]. The study concentrated on the effect of both nanoferrite concentration and particle size on the different investigated properties. Generally, the rheometric and mechanical properties were improved with increasing ferrite load while reduced with increasing its particle size. However, the dielectric constant showed an increase with increasing ferrite load as well as particle size. These results were explained according to the interaction between ferrite nanoparticles and rubber matrix.