Реологические свойства металлонаполненных систем на основе полиэтилена низкой плотности и алюминия

Abstract

The paper considers the fundamental principles of the study of the rheological features of the melt flow of the initial low-density polyethylene and its filled compositions with aluminum powder, depending on the filler concentration, temperature and shear rate. To improve the compatibility of metal-polymer systems, a compatibilizer was used, which is a graft copolymer of low density polyethylene with 5 – 7 wt. % maleic anhydride content. First, the values of the melt flow rate of low density polyethylene were determined depending on the concentration of aluminum powder. The filler concentration was varied in the range 0.5 – 30 wt. %. It is shown that with the loading of 0.5 wt. % aluminum powder, the maximum fluidity of the composites melt is achieved. The flow curves, the dependence of the effective viscosity on the shear rate of the initial low-density polyethylene and composites with 0.5 wt. % and 5.0 wt. % content of aluminum powder were determined. The theoretical substantiation of the regularities of changes in rheological properties is given. The regularity of the change in the effective viscosity of the melt on temperature in Arrhenius coordinates has been established. On the basis of the curves obtained, the values of the activation energy of the viscous flow are determined. It was found that with the loading of the filler, an increase in the activation energy of the viscous flow is observed. A temperature-invariant characteristic of the viscosity properties of composites has been constructed, which makes it possible to predict the change in the value of this indicator at high shear rates, close to their processing by extrusion and injection molding. The developed materials have passed industrial testing at the METAK LLC enterprise in Azerbaijan.