Synthesis, structure, and properties of organic–inorganic nanocomposites containing poly(titanium oxide)

Abstract

Optically transparent hybrid organic–inorganic nanocomposites based on poly(titanium oxide) gels and hydroxyethylmethacrylate (HEMA, with different component ratios, and terpolymers containing lactide or glycolide as a third component) have been synthesized using a two-stage method. Exchange reactions between HEMA and titanium isopropoxide, and hydrolytic polycondensation of titanium alkoxide in the organic monomer agent have been detected. Radical polymerization of HEMA in the presence of poly(titanium oxide) has been studied. The presence of poly(titanium oxide)–oxoethylmethacrylate clusters of 4–6 nm size in the nanocomposites has been established by small-angle X-ray, X-ray phase analysis and secondary ionic mass spectroscopy. The set of physico-mechanical, thermophysical and optical properties of hybrid nanocomposites has been analyzed. Under UV-irradiation of nanocomposites, the single-electron transition Ti⁴⁺ ⇆ Ti³⁺, accompanied by the darkening/discoloring of the sample, took place. The intensity and speed of photochromic transition can be regulated by changing the composition of nanocomposites. The tensile strength of nanocomposites and the temperature of destruction reach 6.8 MPa and 244 °C respectively. The dependence of the properties of nanocomposites on the initial ratio of organic and inorganic components has been established.