Epoxidized natural rubber composites containing K0.15Cr0.02Ni0.83O nanoparticles: Curing characteristics, dynamic mechanical, mechanical, morphological, and dielectric properties

Many researchers have been trying to improve rubber composites because they are commonly used in a wide range of applications. Incorporation of nano-fillers in a rubber matrix is the most acceptable way to improve the mechanical and electrical properties of rubber composites. A nanometer-sized filler, such as K0.15Cr0.02Ni0.83O (KCNO), has rarely been used to improve the properties of rubber composites. Epoxidized natural rubber (ENR) was chosen for blending with KCNO nanoparticles based on its polarity and chemical resistance. The aim of this work is to investigate the effects of filler loading (0.5, 1.5, and 5 phr) on the curing characteristics, dynamic mechanical, mechanical, morphological, and dielectric properties of rubber composites. From the results, rubber vulcanizates with 1.5 phr of KCNO as filler exhibit better tensile strength and 500% modulus compared to other ENR specimens containing KCNO. ENR containing 1.5 phr of KCNO also has a higher storage modulus (E′) and glass transition temperature (Tg). The results of a microstructural characterization on a sample containing 1.5 phr of KCNO show that the natural rubber matrix and KCNO are effectively dispersed, indicating that the rubber and KCNO are likely well-matched, therefore curing simultaneously and forming a continuous phase. Furthermore, ENR containing 1.5 phr of KCNO has a greater dielectric constant (12.87 at 5 kHz) than other samples.