A synthetic methods of polyphenylsilsesquioxane

Spherical polyphenylsilsesquioxane (PPSQ) was synthesized at 80°C through the hydrolysis and condensation of phenyl trichlorosilane (PhSiCl₃), with aluminum chloride (AlCl₃) as assistant reactant. Solution of tetramethylammonium hydroxide (N(CH₃)₄OH) in methanol was used as catalyst. Aqueous solution of AlCl3 is a key factor for the formation of spherical PPSQ. When PhSiCl₃/AlCl₃=6 (molar ratio) and the appropriate amount of N(CH₃)₄OH, PPSQ could be synthesized in high yield and had good thermal stability. The structure of PPSQ was finally characterized by FTIR, Raman, TGA, XRD, ²⁹Si NMR and SEM and so on. Results show that PPSQ chain is of high regularity, on the chain there is no hydroxyl group, and the silicon content in PPSQ is 21.86%. PPSQ synthesized is of high char residue at 850°C.