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Synthesis of Organosilica Films Through Consecutive Sol/Gel Process and Cationic Photopolymerization
Author(s) -
Versace DavyLouis,
Chemtob Abraham,
CroutxéBarghorn Céline,
Rigolet Séverinne
Publication year - 2010
Publication title -
macromolecular materials and engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.913
H-Index - 96
eISSN - 1439-2054
pISSN - 1438-7492
DOI - 10.1002/mame.200900318
Subject(s) - cationic polymerization , photopolymer , materials science , epoxy , sol gel , polymerization , monomer , substituent , polymer chemistry , condensation polymer , silicate , chemical engineering , organic chemistry , polymer , composite material , chemistry , nanotechnology , engineering
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.