The paper discusses the main patterns of structure formation and the production of highly filled polymer composite materials based on a deformable particulate filler from rice straw (agricultural waste) and a dispersion of polyvinyl acetate (PVA) in water. t has been established that when using a deformable filler of rice straw powder, it is possible to obtain under high pressure (up to ~230 MPa) pressing DFPCM with the highly-filled type of structure and the content of dispersed filler up to ~90% by volume. Such PCM has a sufficiently high level of physical and mechanical characteristics - compressive strength ~104 MPa and elastic modulus ~ 3.0 GPa, which opens up opportunities for its wide application and production of products for various purposes from "green chemistry" materials.

The results of investigation of dependence of physical and mechanical characteristics of disperse-filled polymer composite materials (DFPCM) based on EVA grade 11306-075 and rice straw powder with particle size of ~ 250 microns (RSP) on generalized parameters of their structure are presented. The calculation of the generalized parameters and the classification of DFPCM according to the type of structures were carried out.It has been shown that when filling EVA grade 11306–075 with RSP particles, depending on the type of structure, the tensile strength of DFPCM decreases by ~ 2 times (from 9.4 to 4.51 MPa), the tensile strain by more than ~ 10 times (from 275 up to 8%), and the value of the tensile modulus increases by ~ 18 times (from 42 to 750 MPa).To obtain DFPCM based on EVA filled with rice straw powder with optimal physical and mechanical properties, it is recommended to introduce RSP in the concentration range from 0.18 to 0.45 vol.p.

A study on the effect of the structure of disperse-filled polymer composite materials (DFPCM) based on EVA grade 11306-075 and rice straw powder (RSP) with a particle diameter of 250 μm on the complex of rheological properties has been carried out.For the first time, a quantitative relationship of generalized parameters, type of structure and lattices with the rheological properties of dispersed systems based on EVA + RSP has been determined. It has been established that during the processing of DFPCM with the DS, LFS, and MFS-1 structure types by traditional methods (extrusion, injection molding, etc.), there are practically no technological difficulties. Systems with the type of structure MFS-2 and HFS have an increased viscosity (~7–15 times) in comparison with unfilled EVA; therefore, they cannot be processed.The results of the experiments and the approach developed in this work makes it possible to design DFPCM compositions with adjustable structural parameters and a set of properties, as well as to choose methods and technological parameters for processing them into products with a given shape, configuration, and dimensions.

The main methods for determining the maximum content of the dispersed phase and designing the compositions of polymer composite materials (PCM) with different types of dispersed structure are considered on the example of rice straw powder (RSP) particles deforming under pressure.It is shown that different methods for determining the maximum content of RSP in PCM make it possible to obtain data on the packing and internal porosity of RSP particles.It has been established that dispersed RSP particles deform under pressure, and at a pressure of ~500 MPa their density almost reaches the value of the true density of the substance (~1.55 g/cm3).The maximum content of RSP with deformable particles in dispersed PCM can reach ~95 vol.%, which significantly expands the possibilities of polymer materials science and makes it possible to practically solve the environmental problem of using agricultural waste in the form of rice straw.