New Synthetic Route to (3-Glycidoxypropyl)trimethoxysilane-Based Hybrid Organic−Inorganic Materials

Hybrid organic−inorganic materials have been obtained by cohydrolysis of (3-glycidoxypropyl)trimethoxysilane (GPTMS) and tetraethyl orthosilicate (TEOS) in acidic conditions. Boron trifluoride diethyl etherate (BF 3 OEt 2 ) has been used to catalyze the epoxide polymerization. The effect of BF 3 OEt 2 has been studied by multinuclear magnetic resonance (NMR) in the precursor sol and by Fourier transform infrared spectroscopy in the final material. The addition of BF 3 OEt 2 to a prereacted sol of GPTMS and TEOS has allowed the epoxide ring opening at room temperature, without formation of diol units or boric acid precipitation in the final material. The prereaction time of GPTMS with TEOS has been found to be an important parameter. The catalytic effect of BF 3 OEt 2 with respect to other commonly used catalysts in sol−gel processing of GPTMS-based hybrid organic−inorganic materials, such as zirconium butoxide and 1-methylimidazole, has been studied.