Poly(phenylsesquioxane) base silicon resins: synthesis, characterization and structural study by SAXS

TPh, TPhDL and TPhDC silicone resins were prepared by sol-gel method, using phenyltriethoxysilane as a source of TPh repeating units, and poly(dimethylsiloxane), DL, or tetramethyldiethoxydissiloxane, DC, as sources of D segments. The molecular structure of these resins were characterized by FT-IR and 29Si MAS NMR spectra. SAXS traces of TPhDL resins presented a halo associated to a high concentration of scattering units with spatial correlation. The behavior of the SAXS traces for TPhDC were an indication of a random distribution of scattering centers. The nano structure of these materials cannot be described as a system of isolated scattering centers. The electron density contrast was attributed to the presence of regions richer in TPh repeating units. TGA curves evidenced good thermal stability for all resins obtained. (author)