Influence of BaTiO3 Nanoparticles on Dielectric, Thermophysical and Mechanical Properties of Ethylene-Vinyl Acetate Elastomer/BaTiO3 Microcomposites

This paper reports on the effects of nano-BaTiO₃ particles on the dielectric, thermophysical (thermal conductivity) and mechanical properties of ethylene-vinyl acetate (EVM) elastomer/BaTiO₃ microcomposites. The EVM composites with nano-, micro- and nano/micro hybrid BaTiO₃ fillers have been prepared by melt compounding. The results showed that the addition of nano-BaTiO₃ particles to micro- BaTiO₃/EVM composites could lead to an enhancement in permittivity, thermal conductivity and mechanical strength when compared with the micro-BaTiO₃/EVM composites with the same total filler content, whereas the dielectric strength did not show significant difference and the dielectric loss tangent increased slightly. The Maxwell-Garnett effective medium model was used to analyze the BaTiO₃ concentration dependence of relative permittivity of the composites.

I. Introduction

Fillers are extensively used in polymer composites for electrical insulation, not only to enhance the mechanical performance but also to improve other desired properties, such as electrical and thermal properties [1]. The mechanical enhancement of polymer (e.g., elastomer, rubber) composites arises from the nanoscopic dimensions of the fillers and the strong filler-polymer interaction. However, the electrical and thermophysical properties of the composites are primarily determined by the inherent properties of the different components that constitute the materials [2]–[4].