Reactions of trimethylsilylated silicate anions in acidic media. - Part 2 : The influence of reaction parameters

Abstract

It is shown that the ion-exchange resin Amberlyst 15 acts as a powerful proton donor for SiO bond cleavages and rearrangements of trimethylsiloxysiloxanes. In the presence of hexamethyldisiloxane, transformations of trimethylsiloxysiloxanes of different structure show a dual effect: highly caged structures are loosened, while very loose structures become more rigid. Tetrameric ring structures predominate in the reaction products. The transformation reactions are controlled by the acid to hexamethyldisiloxane ratio in the reaction mixture. In the absence of hexamethyldisiloxane trimethylsiloxysiloxanes are highly degraded.