Enhanced dielectric constant and mechanical investigation of epoxidized natural rubber with TM-doped CeO2 nanocomposites

The dielectric constant and mechanical properties of epoxidized natural rubber (ENR) were improved by forming composites with CeO2 and various types of transition metal (TM) doped CeO2 nanoparticles (TM-doped CeO2 such as Fe-CeO2, Co-CeO2, Ni-CeO2, Cu-CeO2, Mn-CeO2 and Zn-CeO2). The CeO2 samples and TM-doped CeO2 nanoparticles were prepared using a co-precipitation method at room temperature and were calcined at 600 degrees C. The composites were prepared with 2 phr of CeO2 and TM-doped CeO2 nano-particles referred to as CeO2 @ENR, Fe-CeO2 @ENR, Co-CeO2 @ENR, Ni-CeO2 @ENR, Cu-CeO2 @ENR, Mn-CeO2 @ENR and Zn-CeO2 @ENR. A carbon black (CB) and ENR composite was also prepared for comparison and referred to as CB@ENR. The morphology, phase and valence states of prepared samples were characterized using transmission electron microscopy (TEM), X-ray diffraction (XRD), field emission scanning electron microscopy, X-ray photoelectron spectroscopy. The samples exhibited XRD peaks and TEM-selected area electron diffraction corresponding to a face centered cubic CeO2 structure, confirming a single phase. They showed average crystallite sizes in the range of 10.5 +/- 0.3-15.0 +/- 1.4 nm. All TM-doped CeO2 @ENR composites exhibited higher dielectric constants and lower dielectric losses at room temperature as a function of frequency than that of CB@ENR composites. A maximum value of similar to 392.6 at 102 Hz for the Cu-CeO2 @ENR composite was shown. Additionally, this dielectric constant was about 3 and 4.7 times higher than those of CeO2 @ENR and CB@ENR, respectively. Also, the breakdown strength of the Cu-CeO2 @ENR nanocomposite was increased compared to CB@ENR. Furthermore, TM-doped CeO2 nanocomposites display increased torque, higher 100% & 300% moduli and greater tensile strength caused by nano-filler affects. As a result, this research may open up new avenues for the development of insulating elastomers.(c) 2022 Elsevier B.V. All rights reserved.