Synthesis of poly(phenylsilsesquioxane) by the aid of phase transfer catalysts

Trichlorophenylsilane (TCP) was hydrolyzed in a toluene/water bilayer solve nt system, and a phenylsilanetriol (PST) was produced in the aqueous layer. To this aqueous PST solution, a phase transfer catalyst was added. The con densation was conducted by refluxing toluene/water to obtain poly (phenylsi lsesquioxane) (PPQS) in the toluene layer in high yield. The resultant PPQS had a branched structure, consisting mainly of a ladder structure. In this polycondensation, PST and the phase transfer catalyst form a salt in the a queous layer, and this salt is transferred to the toluene layer where the c ondensation of PST is induced.