Synthesis of Organosilica Films Through Consecutive Sol/Gel Process and Cationic Photopolymerization

✍ Scribed by Davy-Louis Versace; Abraham Chemtob; Céline Croutxé-Barghorn; Séverinne Rigolet

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 524 KB
• Volume: 295
• Category: Article
• ISSN: 1438-7492
• DOI: 10.1002/mame.200900318

✦ Synopsis

Abstract

The cationic photopolymerization of epoxy polysilsesquioxane resins synthesized through a acid‐catalyzed sol/gel process is studied. To elucidate the effect of the organic substituent on sol/gel reaction kinetics, two organotrimethoxysilanes with different organic groups were employed. Effects of UV irradiation on the microstructure of the epoxy‐functional polysilsesquioxanes were also studied. ^29^Si solid‐state MAS NMR proved that UV‐generated Brönsted acids favored a work‐up of the silicate network by promoting new sol/gel condensation reactions. There was a significant slowdown of epoxy conversion rates with increasing sol aging, which may be due to a competition between an active chain end and an activated monomer mechanism for the epoxy cationic polymerization.

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