Composites consisting of synthetic polymers and natural organic fillers have many applications. Plant-based materials, particularly wood, are used as fillers. Most frequently they are added to the polymer in the shape of wood flour or wood fibres. This type of polymer composite allows the possibility of modifying the components in accordance with the requirements of the application. Modifications to wood flour (WF) were carried out with a 10% solution of maleic anhydride (MA) in acetone in the presence of benzoyl peroxide and dicumene hydroperoxide. Lignin and cellulose were isolated from the WF and modified by the same method as the WF. They were characterized by Fourier Transform infrared spectroscopy and it was proved that there was a chemical reaction between the wood components and MA. This was confirmed by chemical analysis and by a determination of the hydroxyl groups in unmodified and modified WF. Composites of polypropylene and modified WF were obtained and studied by scanning electron microscopy, transmission electron microscopy, dynamic mechanical analysis and mechanical tests. They showed an improvement in adhesion between the polymer and the modified WF

Investigations are reported on the polymerization kinetics of an unsaturated polyester resin, containing both styrene and acrylonitrile (AN), and on the possibility of making it water‐dilutable in order to use it for impregnating organic fibre materials. It is found that the unsaturated polyester resin, containing 31 wt.‐% styrene, can be diluted with almost no limits with acrylonitrile, but when the quantity of acrylonitrile is up to 14% the products are homogeneous and mono‐phase. After alkalizing with ammonium, the unsaturated polyester resin, containing acrylonitrile, becomes soluble in water in which it forms a fine emulsion. On polymerization of the resin, phase reversal takes place, water remaining dispersely included in the hardened resin. The copolymerization rate as a function of the water quantity is studied.

The paper presents the results of computer modeling and prediction of the mechanical properties of composite materials with a polycarbonate matrix filled with short glass inclusions. At the micro-level, the influence of the volume of inclusions on the mechanical properties of the designed composite based on polycarbonate matrix is studied in the DIGIMAT (France) program. It was found that with a ratio of the sizes of inclusions in the range of 468÷60, the particles have a needle shape, and the material with such inclusions has a higher stress limit and elastic modulus than with a shape coefficient less than 50. The components of the fiber orientation tensor were also determined, at which the values of computer modeling are in good agreement with experimental data. The influence of the size of the finite element grid on the characteristics of the composite at the macro level was studied, and recommendations were given for choosing the size of the face of the finite element. The adequacy of computer models was confirmed by the results of field tests. The paper presents the results of testing flat samples made by injection molding technology. Mechanical tests were carried out for three variants of samples made of composite material based on a polycarbonate matrix with 10 %, 20 % and 30 % inclusions. The discrepancy between the experimental and computer results for samples with 10 %, 20 % content of short chopped fibers is explained by the influence of technological factors on the properties of the material at the macro-level. The conducted research allowed us to develop a computer modeling technique used at the stage of development of polymer composites based on thermoplastic matrices with short glass inclusions

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Copper sulfide-containing lignocellulose nanocomposites with improved electroconductivity were obtained. Two methods for preparing the copper sulfide lignocellulose nanocomposites were developed. An optimization of the parameters for obtaining of the nanocomposites with respect to obtaining improved electroconductivity, economy, and lower quantities and concentration of copper and sulfur ions in waste waters was conducted. The mechanisms and schemes of delaying and subsequent connection of copper sulfides in the lignocellulosic matrix were investigated. The modification with a system of 2 components: cupric sulfate pentahydrate (CuSO4. 5H2O) and sodium thiosulfate pentahydrate (Na2S2O3.5H2O) for wood fibers is preferred. Optimal parameters were established for the process: 40 % of the reduction system; hydromodule M=1:6; and ratio of cupric sulfate pentahydrate:sodium thiosulfate pentahydrate = 1:2. The coordinative connection of copper ions with oxygen atoms of cellulose OH groups and aromatic nucleus in lignin macromolecule was observed.