Effect of Mixed Sol-Gel Precursors on the Metal-Oxo Phase Within a UV-Curable Silicone Hybrid Material
✍ Scribed by David P. Dworak; Mark D. Soucek
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 413 KB
- Volume
- 207
- Category
- Article
- ISSN
- 1022-1352
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✦ Synopsis
Abstract
Summary: An inorganic hybrid material was produced using a polysiloxane binder and metal‐oxo‐clusters which were derived from sol‐gel precursors. The continuous phase is composed of an elastomeric polysiloxane functionalized with cycloaliphatic epoxide groups. Pendant alkoxy silane groups serve as a coupling agent to form a network between the metal‐oxo‐clusters and the crosslinked polysiloxane. Methyl, cyclopentyl, and cyclohexyl substituted polysiloxanes were formulated with a variety of sol‐gel precursors (tetraethylorthosilicate oligomers, titanium(IV) iso‐propoxide, zirconium(IV) propoxide, and zinc acetate). Phase‐modulated FT‐IR, X‐ray photoelectron spectroscopy, solid state ^29^Si NMR, and solid state ^13^C NMR were used to investigate the internal structure of the mixed metal‐oxo/silicon‐oxo colloids prepared within the cured polysiloxane matrix. Results indicate that the cycloaliphatic groups inhibit the complete hydrolysis and condensation of the pendant triethoxysilane group and reaction of the sol‐gel precursors. Analysis also indicated that the metal‐oxo‐clusters were comprised of mixed species of sol‐gel precursors resulting in hetero‐bonded (SiOMetal) colloids.
Possible network compositions of the cured material (a) specific metal‐oxo‐clusters, (b) hetero‐bonded metal‐oxo‐clusters, and (c) core/shell type metal‐oxo‐cluster configuration.
magnified imagePossible network compositions of the cured material (a) specific metal‐oxo‐clusters, (b) hetero‐bonded metal‐oxo‐clusters, and (c) core/shell type metal‐oxo‐cluster configuration.