Introduction. The widespread use of polymer materials in the construction industry for the production of thermal insulation products based on them is largely due to the ability to obtain a highly porous polymer matrix with high specific strength and chemical resistance. Among thermal insulation polymer materials, polyurethane foam is of particular interest, exhibiting a thermal conductivity of up to 0.02 W/(m·K). How-ever, its significant drawback is flammability, which limits its application. Research is underway to mitigate this drawback through chemical modification, for example, with a silicate component in crystalline hydrate form. The purpose of this work is defined, which is to investigate the effect of the silicate component on the performance properties of pour-in-place rigid polyurethane foam and to establish the relationship with the resulting pore structure of the composites. Materials and methods. An organomineral thermal insulation composite based on a reactive mixture for the synthesis of rigid pour-in-place polyurethane foam, modified with a silicate component – sodium meta-silicate pentahydrate Na₂SiO₃·5H₂O of fraction (0.9–1.25 mm). It was produced by free foaming of the reac-tion mixture components. For modification, a silicate component was added to the mixture in quantities of 15, 30, 45, 60, 75, and 90% of the reactive composition. The prepared mixture hardened within 24 hours at a temperature of 22±3°C. The performance properties of the composite material were determined in accordance with regulatory documents. Results. It was found that the modification accelerates the processes of foam and polymer formation. However, due to the high true density of sodium metasilicate, initially, upon introducing 15% of the silicate component into the system, the density of the composite decreases from 51 kg/m³ to 33 kg/m³. A further increase in the concentration of the silicate-containing component up to 90% leads to an increase in density to 77 kg/m³. The compressive strength at 10% strain drops by 50% upon introducing 15% of the silicate component (from 0.46 to 0.23 MPa), but with a further increase in concentration, it recovers to 0.36 MPa. The specific strength of the organic polymer matrix changes only slightly (a decrease of no more than 11%), indicating the maintenance of its load-bearing capacity. Thermal conductivity increases moderately from 0.022 to 0.029 W/(m K), assisted by the preservation of high porosity (94–97%) and a closedcell, uniform pore structure. It is noted that the main contribution to the reduction in thermal insulation ability and flammability is provided by the highly thermally conductive silicate component in amounts of 60–90%. Conclusions. The conducted complex of studies allowed us to establish the optimal composition of the composite material. It is recommended to saturate the rigid pour-in-place polyurethane foam composition with the silicate component in the range of 45–60% of its content.
Lipka et al. (Sat,) studied this question.