Arylene-bridged 2,2,5,5-tetramethyl-2,5-disila-1-oxacyclopentanes as precursors to non-shrinking polysiloxanes. A new route to sol-gel type polymers

The first member of a new class of sol-gel monomers which can easily be ring-opening polymerized to give a highly crosslinked polymer was successfully prepared. Monomer 4 reacted with catalytic tetrabutylammonium hydroxide to afford a transparent gel. The ring-opening polymerization reaction eliminated the problems associated with normal sol-gel condensation byproducts and since water is not required for hydrolyzing alkoxide groups, solvent can also be eliminated.