Research of the influence of ingredients on electrophysical properties of nanomodified fire-safe polymer compositions with magnesium oxide dihydrates

Abstract

The purpose of the article is to determine the influence of physico-chemical properties and concentration of modifiers, the type and dispersion of magnesium oxide dehydrates and the polymer matrix on the electrophysical properties of fire-fighting composite materials of copolymer ethylene with vinyl acetate. Copolymer compositions with a flux rate of 2,5 g/10 min and 5 g/10 min, magnesium oxide dihydrates with a mean median diameter of particles of 3 μm and 3,7 μm were studied, amino silanes with a dynamic viscosity of 2 MPa · s and 2,5 MPa ∙ s. Methods for determination of electric strength, volume electric resistance, tangent of dielectric loss angle, dielectric permittivity were used for conducting researches. For this purpose, a device for testing isolation, an electric resistive resistance meter, and an AC bridge were used. In order to compare these indices, for each polymer composition, the graphs were based on the content of the ingredients. Electrophysical characteristics have been obtained, which allow determining the composition that provides optimal values for insulating materials with increased fire safety requirements. Electrophysical investigations were first used to determine the effect of the properties of polymer compositions on electrical strength, specific volumetric electrical resistance, tangent of the angle of dielectric losses, dielectric permeability. The electrical strength rises from 25,5 kV/mm to 30 kV/mm, the specific volumetric electric resistance rises from 4 ∙ 1012 Ω cm to 6 ∙ 1014 Ω cm, the dielectric constant decreases to 3,8 and the tangent the angle of dielectric loss to 0,0055. The results of researches should be used for the development of the composition of fire-safe polymer compositions for cable products.