Порівняльний аналіз характеристик міцності вітчизняних композитних матеріалів на поліуретановій основі

The article presents the results of a comparative analysis of the physical and mechanical properties of two domestic composite materials based on polyurethane - DK2 (developed by Priazovsky State Technical University) and AK.UR-03 (manufactured by Kapitel, Dnipro). The study is aimed at determining the ultimate compressive strength of materials and assessing their deformability, which is a critical factor in the selection of materials for the protection of equipment operating under high loads. Particular attention is also paid to the analysis of the porosity of materials as one of the key parameters affecting their durability and performance. Experimental tests were conducted on a 10-ton hydraulic press with a gradual increase in load. The change in the thickness of the samples at each stage was measured to calculate the degree of deformation and stresses. The results showed that the DK2 material demonstrates higher strength (209 MPa vs. 170 MPa for AK.UR-03) and significantly lower relative strain (12.5 % vs. 43 %, respectively). This indicates the feasibility of its use in structures where strength and dimensional stability under load are critical. In addition to the mechanical analysis, the porosity of the materials was studied using a 3D macroscope after their destruction in the cooled state. For the DK2 material, 977 pores were found, which occupied about 9.79 % of the surface area of the studied surface. The cause of pore formation was determined to be a chemical reaction between isocyanates and humidity, which results in the release of carbon dioxide, creating microbubbles in the polymer structure. Methods of reducing porosity, including the introduction of dispersed fillers (graphite, copper oxide), which can bind CO₂, improving the homogeneity of the structure and strength of the composite, have been proposed. The practical significance of the results lies in the possibility of effective use of the DK2 material in the mining, metallurgical, mechanical engineering, and energy industries to restore and protect equipment operating under heavy loads and aggressive environments. The work also opens up prospects for further research to improve the performance of polymer composites by modifying their structure and composition