Synthesis of Inorganic Polymers as Glass Precursors and for Other Uses. Preceramic Block or Graft Copolymers as Potential Precursors to Nanocomposite Materials.

摘要

Preceramic block or graft copolymers may offer entree into nanocomposite ceramics provided the two homopolymers are immiscible and one can carefully control the size of the blocks or grafts. We are exploring the possibility of making copolymers from methlsilsesquioxane, -(MeS(O)1.5)(x-), (SiO), a precursor to black glass and the polysilazane, -(MeHSiNH)(x-), (SiMe), (SiMe), a precursor to silicon carbide nitride. Our initial efforts have been directed towards delineating the chemical transformations that SiO, prepared by room temperature catalytic redistribution of -(MeHSiO)(x-) using Cp2 TiMe2 as the catalyst (0.1 wt%), undergoes as it is heated to 900 C in N2. We find that although Cp2TiMe2 will not catalyze the redistribution of SiMe at room temperature; in the presence of even small amounts of -(MeHSiO) (x-), it is an active catalyst precursor and copolymer be formed. Spectral and chemical composition studies on the pyrolysis products of the copolymers and SiO are described. (AW)