Structure and Properties of Epoxy Composites Modified with Titanium Oxide Filler

Glass-like epoxy-titanium oxide composites were obtained using amine curing and sol-gel method for the formation of nanofiller from titanium tetra-n-butoxide directly in the polymer binder. As a polymer matrix of the composites, the product of polycondensation of low-viscosity epoxy resin ST-3000 and polyetheramine Jeffamine T-403 was used. The titanium dioxide content in the composites was 0.5–10 wt %. The structure of the obtained composites was studied by Raman spectroscopy and electron microscopy, and a detailed thermomechanical analysis of the samples was performed. The titanium oxide nanofiller forms a three-dimensional network in the organic polymer matrix, and such an inorganic framework reinforces the polymer. With an increase in TiO2 concentration, the temperature of the beginning and the temperature of completion of the transition of the composites to a highly elastic state significantly increase. The mass-fractal structural organization of titanium dioxide in the composites determines the lower deformability of the samples. Interphase transition layers with different segmental mobility were detected in the structure of the composites. In these layers, during the formation of epoxy-titanium oxide composites, filler/matrix interaction occurs with the formation of chemical covalent bonds. The features of the composites’ structure affect the operational properties, in particular, the protective properties of coatings based on them. It was established that thin composite coatings can provide corrosion resistance of 315 kΩ cm2 on the surface of the D16 aluminum alloy. The efficiency of corrosion protection of the substrate was 70–90%, depending on the filler concentration in the coatings.