EFFECT OF THE SIZE OF INCLUSIONS ON STRUCTURAL ORGANIZATION AND DEFORMATION BEHAVIOR OF HIGH-DENSITY FILLED POLYETHYLENE WITH DIFFERENT MOLECULAR MASS*

In this work, we examine the effect of the content and dispersion of the filler on the structural organization, mechanical properties, and microdeformation behavior of composites based on HDPE with various MM and aluminum hydroxide [AI(OH)3]. The main characteristics of the initial components are presented in Tables 1 and 2. The filler material was produced by polymerization of ethylene in the presence of a catalytically activated filler [3]. When using hydrogen as the regulator of MM, this method makes it possible to produce composites in a wide range of MM values of the polymer matrix [4]. In this work, we examined composites based on PESH~ (MM = 1.5.106 ) and PEMMM (~fl.1 = 12"i0~). The composites were also produced by mixing in a melt of PEM~ and AI(OH) 3 with additions of 2% calcium stearate and 0.5% Irganox. Tensile tests on compacted specimens in the form of blades were carried out at a relative strain rate of 0.67 min-1o The structure of the material was examined in a scanning electron microscope (SEM) and also by the methods of wide-angle and small-angle x-ray diffraction [5] and the method of infrared (IR) Fourier spectroscopy. Deformation processes were examined by the in situ method of deformation of the specimens in the chamber of the SEM. Structural Organization of Filled Composites Analysis of the wide-angled fraction patterns of the initial components and of composites based on these components showed that the positions of the crystalline maxima of the individual components in the composite remain unchanged. Because of the isolation of the crystalline maxima of the individual components which is a typical feature of the diffraction patterns of the filled systems, the contribution of dispersion of the filler can be taken into account accurately. This procedure yielded the profiles of wide-angled scattering of the polyethylene matrix in the composite material. These profiles were similar to the scattering profile of the initial HDPE. Calculation of the absolute values of the degree of the crystallinity of the matrix material, carried out using the method described in [6], showed that within the limits of accuracy of the experiment ( the degree of crystallinity does not depend on the content and dispersion of the filler and corresponds to the values obtained for the initial HDPE. Analysis of the small-angle diffraction patterns of the initial components and filled composites showed that the special features of