Synthesis and Characterization of Organically Modified Silicates Obtained by Co-condensation of Two Organic – Inorganic Ureasilicate Monomers

Transparent organic-inorganic ureasilicate materials (ureasils) were synthesized by hydrolysis and co-condensation of two organic – inorganic precursors, obtained by reactions between 3-isocyanatepropyltriethoxysilane (ICPTES) and double terminated polyetheramine (Jeffamine), and between ICPTES and 3-aminopropyl triethoxysilane (APTES), respectively. The prepared samples were characterized by optical UV – VIS spectroscopy, small-angle X-ray scattering (SAXS), FTIR spectroscopy and the depth sensing indentation method (DSI). It is shown that the molar ratio between the initial components influences on the mechanical and optical properties of the materials in the investigated range.