Refractive Index Change during Photo Crosslinking Reaction of Poly (silsesquioxane) Derivatives Containing Cinnamoyl Moieties in the Side Chains

Abstract

The synthesis and refractive-indices properties of poly (silsesquioxane) [poly (SCC)] derivatives with pendant cinnamoyl (CI) groups were examined. The obtained poly (SCC) derivatives had good thermal stabilities, good solubilities in the common organic solvents, and good film-forming properties. The photo-chemical reaction of the films prepared from poly (SCC) derivatives were examined under UV-irradiation (1.80-2.00 mW/cm2 at 313 nm), and it was found that the photo-dimerization of CI proceeded smoothly to afford the corresponding cross-linking films. The refractive-indices of the resulting films were measured by ellipsometry, and it was found that the large changes (Δn_D's = 0.073) of refractive indices occurred before and after photo-chemical reactions.