Enhanced dielectric, energy storage and tensile properties of BaTiO3–NH2/low-density polyethylene nanocomposites with POE-GMA as interfacial modifier

Dielectric polymer nanocomposites with excellent dielectric performance and high discharge energy storage are important for capacitor applications. In this study, γ-Aminopropyl triethoxysilane (γ-APS) grafted BaTiO3 nanoparticles (BaTiO3–NH2) were used as filler to improve the dielectric and energy storage properties of low-density polyethylene (LDPE). Glycidyl methacrylate grafted ethylene-octene copolymer (POE-GMA) was used as interfacial modifier between LDPE and BaTiO3–NH2 particles. Because of the chemical reaction between the epoxy groups of POE-GMA and the amino groups of BaTiO3–NH2, the soft shell/hard core structure of POE-GMA@BaTiO3–NH2 can be formed during the blending process. The BaTiO3–NH2/POE-GMA/LDPE nanocomposites with superior dielectric properties were obtained. When the contents of POE-GMA and BaTiO3–NH2 were 10 wt%, the favorable breakdown strength of 350 MV/m and fine discharged energy density of 2.46 J/cm3 for BaTiO3–NH2/POE-GMA/LDPE blend were achieved. This work provided a useful and easy way to exploit perspective dielectric candidates for energy-storage applications. •Core-shell structured POE-GMA@BaTiO3–NH2 nanoparticles were designed to improve the energy storage of LDPE.•Soft shell/hard core structure reduced interfacial defects and decreased electric field stress concentration.•The favorable breakdown strength of 350 MV/m and fine discharged energy density of 2.46 J/cm3 were achieved.