Use of Metal Oxide–Silica Fillers NiО‒SiO2 and СuO‒SiO2 as Active Modifiers of Polyurethane Composites

The possibility of using metal oxide–silica fillers as active modifiers of polyurethanes synthesized from hydroxyl-containing oligomers and a polyfunctional isocyanate was examined. The curing kinetics of the polyurethane compound in the presence of filler was studied by rotation viscometry. The dependence of the curing rate constants on the specific surface area of the fillers was revealed. The Raman spectra show that introduction of metal oxide–silica fillers in the course of polyurethane synthesis favors the formation of new chemical bonds, including hydrogen bonds, which influences the polymer structure formation. Factors responsible for the enhancement of the strength of the polyurethanes synthesized in the presence of metal oxide–silica fillers were analyzed. Introduction of 0.5 wt % filler favors preparation of the material with improved rheological and physicomechanical characteristics compared to the unmodified polyurethane.