Hydrocarbon-bridged polysiloxane and polysilsesquioxane network materials

Hexylene- and phenylene-bridged polymethylsiloxane xerogels X-2 and X-4, respectively, were prepared by the sol-gel hydrolysis and condensation of 1,6-bis(diethoxymethylsilyl)hexane 1 and 1,4-bis(diethoxymethysilyl)benzene 2 under acidic and basic conditions. These polymerizations afforded network polymers in the form of wet gels within several hours. The gels were processed to afford xerogels whose characteristics (determined by solid state ¹³C and ²⁹Si CP MAS NMR spectroscopy and nitrogen sorption porosimetry) were compared and contrasted with those of their analogous polysilsesquioxanes. ²⁹Si CP MAS NMR indicates a high degree of hydrolysis and polycondensation; porosimetry measurements reveal that the materials have significant surface areas, save for the acid-catalyzed hexylene gels X-2.