Carbamide Composition With Quartz Fillers And Hydrogel Additives

The paper presents the results of experimental studies of the effect of hydrogel additives on the physical-mechanical and structural properties of carbamide compositions with quartz filler. The aim of the study was to determine the optimal hydrogel content, which ensures maximum strength and thermal stability of the composition. The samples were made with a different content of hydrogel additives (0.05–0.17% by weight of the filler), taking into account the amount of free water released during polycondensation of carbamide-formaldehyde resin. The optimal compressive strength (88.0 MPa) was achieved with a hydrogel content of 0.13%, which corresponds to the binding of 75% free water. A further increase in dosage led to a decrease in strength due to excessive moisture binding and changes in hardening conditions. IR spectroscopic analysis showed that the introduction of a hydrogel additive promotes the formation of stronger hydrogen bonds between the components of the composition and reduces the hydrophilicity of the quartz filler. Electron microscopic studies have revealed an ordered microstructure with a decrease in interfacial stresses and porosity. Based on the results of thermogravimetric analysis, it was found that hydrogel compositions have a lower mass loss when heated to 830 ° C, which indicates an increase in their heat resistance. Thus, it was found that the optimal content of the hydrogel additive is 0.13% of the mass of the filler, which increases the strength of the carbamide composition by 20-25%, reduces microporosity and improves the thermal stability of the material.