INORGANIC-ORGANIC POLYMERS DERIVED FROM FUNCTIONAL SILICIC-ACID DERIVATIVES BY ADDITIVE REACTION

Inorganic-organic polymers were synthesized by additive reaction of vinyl-, allyl-, and H-silylated double four-ring (D4R) silicic acids and polymeric silicic acids. The structure and properties of the hybrid polymers were investigated by means of Si-29 NMR spectroscopy, thermoanalysis and BET nitrogen adsorption measurements. Using the defined vinylsilylated D4R silicic acid [(CH2=CH)(CH3)(2)Si]8Si8O20 and the corresponding H-silylated compound [(CH3)(2)HSi]8Si8O20 as precursors, the additive reaction results in a microporous polymer with a ordered Si8O20 substructure. The structural units are connected by six-membered bridges. Shorter (four-membered) or longer (seven-membered) bridges between D4R cages lead to non-porous polymeric materials. The connection of water-glass-derived silicic acid units by six-membered bridges similarly leads to porous polymers with specific surface areas of 500 m(2)/g. For the preparation of the porous hybrid polymers a new, simple two-step reaction route is described.