Preparation and Properties of Organo-Silicon-Phosphorus Hybrid Compounds Based on 3-Aminopropyltriethoxysilane, Tetraethoxysilane, and (1-Hydroxyethylidene)diphosphonic Acid

Abstract The reaction of 3-aminopropyltriethoxysilane with (1-hydroxyethylidene)diphosphonic acid in 96% ethanol results in the 3-hydroxy(ethoxy)silylpropylaminium salt of (1-hydroxyethylidene)diphosphonic acid. The compound dissolves in water and is regenerated after evaporation and drying in air and in vacuum. The initial low-porous xerogel and the products of its pyrolysis in air and in an inert atmosphere are amorphous phases with impurities of crystalline components. The reaction of tetraethoxysilane with (1-hydroxyethylidene)diphosphonic acid leads to a completely amorphous non-porous condensation product, which loses 57% of its weight after treatment with water.