Реологические свойства композитов на основе гидроксида алюминия и смесей полиэтилена низкой и высокой плотности

Abstract

The results of the study of the rheological characteristics of low- and high-density polyethylene blend in the ratio of 50 : 50 and its composites filled with aluminum hydroxide are presented. The influence of the concentration of aluminum hydroxide, temperature, and shear stress on the regularity of changes in the effective viscosity and shear rate has been established. Rheograms of low- and high-density polyethylene blend in the ratio of 50 : 50 and composites based on it are presented. The dependence of viscosity on temperature in Arrhenius coordinates is determined, according to which the “apparent” activation energy of viscous flow for the initial low- and high-density polyethylene blend and its composites filled with aluminum hydroxide varies in the range of 6–19 and 11–31 kJ/mol, respectively. A universal temperature-invariant characteristic of the viscosity properties of low-and high- density polyethylene blend in the ratio of 50 : 50 and its composites filled with aluminum hydroxide, which makes it possible to predict the change in the melt viscosity of composites in a wide range of shear rates and stresses, is drawn. It is shown that, with an increase in the concentration of aluminum hydroxide in the polymer mixture to 5 wt %, the value of the shear rate remains almost unchanged relative to the initial low- and high-density polyethylene blend (50/50). Rheological studies of the melt of polymer materials have been carried out in accordance with the standard ASTM D1238 on a CEAST MF50 capillary rheometer (INSTRON, Italy) in the temperature range of 190–250°C and in the load range of 3.8–21.6 kg.